Playback transitions

ABSTRACT

Examples described herein relate to transitioning a playback session between portable playback devices such as “smart” headphones, earbuds, and handheld speakers with playback devices of a zone-based media playback system. Exemplary techniques facilitate continuity of playback when transitioning between locations (e.g., from at home to on-the-go or vice versa) or between listening paradigms (e.g., personal or out-loud playback of audio content). An example implementation includes detecting a swap trigger, determining the source playback device(s) and target playback device(s), and performing a playback session swap between the source playback device(s) and target playback device(s).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/805,269, filed Jun. 3, 2022, which is a continuation of U.S. patentapplication Ser. No. 16/805,130, filed Feb. 28, 2020, now U.S. Pat. No.11,356,77, which claims the benefit under 35 U.S.C. § 119 of U.S. PatentApplication No. 62/811,962, filed Feb. 28, 2019, each of which areincorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure is related to consumer goods and, moreparticularly, to methods, systems, products, features, services, andother elements directed to media playback or some aspect thereof.

BACKGROUND

Options for accessing and listening to digital audio in an out-loudsetting were limited until in 2002, when SONOS, Inc. began developmentof a new type of playback system. Sonos then filed one of its firstpatent applications in 2003, entitled “Method for Synchronizing AudioPlayback between Multiple Networked Devices,” and began offering itsfirst media playback systems for sale in 2005. The Sonos Wireless HomeSound System enables people to experience music from many sources viaone or more networked playback devices. Through a software controlapplication installed on a controller (e.g., smartphone, tablet,computer, voice input device), one can play what she wants in any roomhaving a networked playback device. Media content (e.g., songs,podcasts, video sound) can be streamed to playback devices such thateach room with a playback device can play back corresponding differentmedia content. In addition, rooms can be grouped together forsynchronous playback of the same media content, and/or the same mediacontent can be heard in all rooms synchronously.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of the presently disclosed technologymay be better understood with regard to the following description,appended claims, and accompanying drawings, as listed below. A personskilled in the relevant art will understand that the features shown inthe drawings are for purposes of illustrations, and variations,including different and/or additional features and arrangements thereof,are possible.

FIG. 1A is a partial cutaway view of an environment having a mediaplayback system configured in accordance with aspects of the disclosedtechnology.

FIG. 1B is a schematic diagram of the media playback system of FIG. 1Aand one or more networks.

FIG. 1C is a block diagram of a playback device.

FIG. 1D is a block diagram of a playback device.

FIG. 1E is a block diagram of a network microphone device.

FIG. 1F is a block diagram of a network microphone device.

FIG. 1G is a block diagram of a playback device.

FIG. 1H is a partially schematic diagram of a control device.

FIGS. 1 -I, IJ, IK, and 1L are schematic diagrams of corresponding mediaplayback system zones.

FIG. 1M is a schematic diagram of media playback system areas.

FIG. 2A is a front isometric view of a playback device configured inaccordance with aspects of the disclosed technology.

FIG. 2B is a front isometric view of the playback device of FIG. 3Awithout a grille.

FIG. 2C is an exploded view of the playback device of FIG. 2A.

FIG. 3A is a front view of a network microphone device configured inaccordance with aspects of the disclosed technology.

FIG. 3B is a side isometric view of the network microphone device ofFIG. 3A.

FIG. 3C is an exploded view of the network microphone device of FIGS. 3Aand 3B.

FIG. 3D is an enlarged view of a portion of FIG. 3B.

FIGS. 4A, 4B, 4C, and 4D are schematic diagrams of a control device invarious stages of operation in accordance with aspects of the disclosedtechnology.

FIG. 5 is front view of a control device.

FIG. 6 is a message flow diagram of a media playback system.

FIG. 7A is a partial cutaway view of an environment having a mediaplayback system configured in accordance with aspects of the disclosedtechnology.

FIG. 7B is a block diagram of a portable playback device configured inaccordance with aspects of the disclosed technology.

FIG. 7C is a front isometric view of a portable playback deviceimplemented as headphones configured in accordance with aspects of thedisclosed technology.

FIG. 7D is a front isometric view of a portable playback deviceimplemented as earbuds configured in accordance with aspects of thedisclosed technology.

FIG. 7E is a front isometric view of a portable playback deviceconfigured in accordance with aspects of the disclosed technology.

FIG. 7F is a front isometric view of a portable playback device with adevice base configured in accordance with aspects of the disclosedtechnology.

FIG. 7G is a schematic diagram illustrating an example pairingconfiguration between a portable playback device and a control device.

FIG. 8A is a schematic diagram illustrating an example push swap inaccordance with aspects of the disclosed technology.

FIG. 8B is a schematic diagram illustrating an example pull swap inaccordance with aspects of the disclosed technology.

FIG. 8C is a schematic diagram illustrating an example push swap inaccordance with aspects of the disclosed technology.

FIG. 9 is a schematic diagram illustrating an example audio-basedidentification technique in accordance with aspects of the disclosedtechnology.

FIG. 10 is a schematic diagram illustrating example control schemes inaccordance with aspects of the disclosed technology.

FIG. 11 is a schematic diagram illustrating example feedback techniquesin accordance with aspects of the disclosed technology.

FIGS. 12A and 12B are example messaging diagrams to illustrating exampleplayback session swap techniques.

FIG. 13A is a method flow diagram illustrating an example swap pulltechnique in accordance with aspects of the disclosed technology.

FIG. 13B is a method flow diagram illustrating an example swap pushtechnique in accordance with aspects of the disclosed technology.

FIG. 14 is a method flow diagram illustrating an example home theaterswap technique in accordance with aspects of the disclosed technology.

FIG. 15 is a method flow diagram illustrating a technique to facilitatea playback session swap in accordance with aspects of the disclosedtechnology.

FIG. 16A is a schematic diagram illustrating an example pairingconfiguration between a portable playback device and a bridge device.

FIG. 16B is a block diagram of a bridge device configured in accordancewith aspects of the disclosed technology.

FIG. 16C is a front isometric view of a bridge device configured inaccordance with aspects of the disclosed technology.

FIG. 16D is a view of a touch-sensitive region implemented in a bridgedevice configured in accordance with aspects of the disclosedtechnology.

FIG. 16E is a front view of a bridge device configured in accordancewith aspects of the disclosed technology.

FIGS. 17A, 17B, 17C, 17D, 17E, and 17F are schematic diagrams of abridge device user interface in various stages of operation inaccordance with aspects of the disclosed technology.

FIG. 18A is a view of an example arrangement between a bridge device anda device base.

FIG. 18B is a view of an example arrangement between a portable playbackdevice, a bridge device and a device base.

FIG. 18C is a view of an example arrangement between a first portableplayback device, a bridge device, a second portable playback device, anda device base.

FIGS. 19A, 19B, and 19C are schematic diagrams of a control device userinterface in various stages of operation in accordance with aspects ofthe disclosed technology.

FIGS. 20A, 20B, and 20C are example messaging diagrams to illustratingexample playback session swap techniques.

FIGS. 21A, 21B, and 21C are schematic diagrams of a control device userinterface in various stages of operation in accordance with aspects ofthe disclosed technology.

FIGS. 22A, 22B, 22C, and 22D are diagrams illustrating exampleproximity-based playback session swaps.

FIG. 23A is a front isometric view of earbuds configured in accordancewith aspects of the disclosed technology.

FIG. 23B is a bottom view of a charging case configured in accordancewith aspects of the disclosed technology.

FIG. 23C is a top view of the charging case.

FIG. 23D is a first side view of the charging case.

FIG. 23E is a second side view of the charging case.

FIG. 23F is a front isometric view of earbuds illustrating exemplaryarrangement with the charging case.

FIG. 23G is an isometric view of the earbud.

FIG. 23H is a first side view of the earbud.

FIG. 231 is a second side view of the earbud.

FIG. 23J is a third side view of the earbud.

FIG. 23K is a fourth side view of the earbud.

FIG. 23L is a fifth side view of the earbud.

FIG. 23M is a sixth side view of the earbud.

FIG. 24A is a front isometric view of a portable playback deviceimplemented as a handheld speaker configured in accordance with aspectsof the disclosed technology.

FIG. 24B is a side view of the portable playback device.

FIG. 24C is a top view of the portable playback device.

FIG. 24D is a bottom view of the portable playback device.

FIG. 24E is a front isometric view of the portable playback deviceillustrating exemplary arrangement with a device base.

FIG. 24F is a front isometric view of the portable playback deviceillustrating exemplary user inputs to the portable playback device.

FIG. 25A is a front view of headphones configured in accordance withaspects of the disclosed technology.

FIG. 25B is a first side view of the headphones.

FIG. 25C is a second side view of the headphones.

FIG. 26A is a front view of headphones configured in accordance withaspects of the disclosed technology.

FIG. 26B is a first side view of the headphones.

FIG. 26C is a second side view of the headphones.

The drawings are for the purpose of illustrating example embodiments,but those of ordinary skill in the art will understand that thetechnology disclosed herein is not limited to the arrangements and/orinstrumentality shown in the drawings.

DETAILED DESCRIPTION I. Overview

Example techniques described herein relate to transitioning a playbacksession between wearable playback devices, such as “smart” headphonesand earbuds, and playback devices of a zone-based media playback system.Further example techniques relate to transitioning a playback sessionbetween portable (e.g., battery-operated, carryable) playback devicesand playback devices of a zone-based media playback system. Suchtransitions are referred to herein as “swaps” or “playback sessionswaps.” Such exemplary swap techniques facilitate continuity of playbackwhen transitioning between locations (e.g., from at home to on-the-go orvice versa) or between listening paradigms (e.g., personal or out-loud).Further, some exemplary techniques may reduce the extent of user input(or other user involvement) involved with transitioning playback ascompared with some other techniques.

In an illustrative example, a user begins a playback session onexemplary headphones while on-the-go. For instance, a user beginslistening to KEXP Seattle using earbuds paired with a mobile device(e.g., a smartphone) over a wireless connection such as 802.15(Bluetooth®) or 802.11, among other examples. In this example, KEXPradio is streamed via the Internet to the mobile device.

Upon arriving home, the user may desire to continue listening to KEXPradio out-loud. To initiate a playback session swap from the earbuds toa playback device within the kitchen, the user may provide an input tothe earbuds. Since the earbuds have a playback session on-going, thisinput designates the earbuds as the source of the playback session swap.The target of the swap (i.e., the kitchen zone) may have been previouslydesignated in a pre-defined swap pair with the earbuds or may bedetermined after the input using a proximity detection technique, suchas audio chirps, as described in further detail herein. The earbudsand/or mobile device perform the playback session swap with the kitchenzone, and playback of KEXP radio continues uninterrupted out-loud on theplayback device within the kitchen.

In another illustrative example, the user may begin a playback sessionon an exemplary portable speaker. For instance, a user begins listeningto WBEZ Chicago using the handheld speaker in a dining room. In thisexample, WBEZ Chicago is streamed via the Internet to the handheldspeaker over a home local area network. Desiring to meditate, the usercarries the handheld speaker to the living room and asks a voiceassistant service to play meditation music. The handheld speaker playsan acknowledgement from the voice assistant service and begins playingback a curated meditation playlist from a streaming audio service.

While playing the curated meditation playlist, the user's friend entersthe living room and suggests that the user check out the new ChildishGambino track, which is playing via a control application on hersmartphone. To initiate a playback session swap from the smartphone tothe handheld speaker, the friend holds the smartphone close to thehandheld speaker to initiate a Near-Field Communication (NFC) exchangebetween the smartphone and handheld speaker. This exchange designatesthe smartphone as the source of the playback session swap and thehandheld speaker as the target. The smartphone performs the playbacksession swap with the handheld speaker, and playback of the ChildishGambino track continues uninterrupted out-loud on the handheld speaker.

To enjoy the Childish Gambino track with more powerful amplifier(s)and/or larger transducer(s), the user initiates a playback session swapfrom the handheld speaker to a playback device in the living room byproviding an input to the handheld speaker. This input designates thehandheld speaker as the source of the playback session swap. Thehandheld speaker automatically designates the living room zone as theswap target based on detected proximity of the handheld speaker to theliving room zone. The handheld speaker performs the playback sessionswap with the living room zone, and playback of the Childish Gambinotrack continues uninterrupted out-loud on the playback device within theliving room.

In a third illustrative example, in the evening, the user may begin aplayback session in the bedroom on a soundbar device that plays backaudio content from a television. Desiring to keep the volume down so asnot to disturb her partner trying to put their baby to bed in anadjacent room, the user initiates a playback session swap from thesoundbar device to the handheld speaker, which she has placed on hernightstand. Since the handheld speaker is physically closer to the user,she can comfortably hear the audio from the television at a lower volumelevel.

After putting the baby to sleep, the partner comes into the bedroom tofind the user asleep. To initiate a playback session swap from thehandheld speaker to a pair of headphones, the partner may provide aninput to the headphones. This input designates the headphones as thetarget of the playback session swap. The source of the swap (i.e., thehandheld speaker) is determined based on context (i.e., based on anactive playback session). The handheld speaker performs the playbacksession swap with the headphones, and playback of the television audiocontinues uninterrupted out-loud on the headphones.

As noted above, example techniques described herein involve playbacksession swaps. An example implementation includes detecting a swaptrigger, determining the source playback device(s) and target playbackdevice(s), and performing a playback session swap between the sourceplayback device(s) and target playback device(s).

While some examples described herein may refer to functions performed bygiven actors such as “users,” “listeners,” and/or other entities, itshould be understood that this is for purposes of explanation only. Theclaims should not be interpreted to require action by any such exampleactor unless explicitly required by the language of the claimsthemselves.

Moreover, some functions are described herein as being performed “basedon” or “in response to” another element or function. “Based on” shouldbe understood that one element or function is related to anotherfunction or element. “In response to” should be understood that oneelement or function is a necessary result of another function orelement. For the sake of brevity, functions are generally described asbeing based on another function when a functional link exists; however,such disclosure should be understood as disclosing either type offunctional relationship.

In the Figures, identical reference numbers identify generally similar,and/or identical, elements. To facilitate the discussion of anyparticular element, the most significant digit or digits of a referencenumber refers to the Figure in which that element is first introduced.For example, element 110 a is first introduced and discussed withreference to FIG. 1A. Many of the details, dimensions, angles and otherfeatures shown in the Figures are merely illustrative of particularembodiments of the disclosed technology. Accordingly, other embodimentscan have other details, dimensions, angles and features withoutdeparting from the spirit or scope of the disclosure. In addition, thoseof ordinary skill in the art will appreciate that further embodiments ofthe various disclosed technologies can be practiced without several ofthe details described below.

II. Suitable Operating Environment

FIG. 1A is a partial cutaway view of a media playback system 100distributed in an environment 101 (e.g., a house). The media playbacksystem 100 includes one or more playback devices 110 (identifiedindividually as playback devices 110 a-n), one or more networkmicrophone devices (“NMDs”), 120 (identified individually as NMDs 120a-c), and one or more control devices 130 (identified individually ascontrol devices 130 a and 130 b).

As used herein the term “playback device” can generally refer to anetwork device configured to receive, process, and output data of amedia playback system. For example, a playback device can be a networkdevice that receives and processes audio content. In some embodiments, aplayback device includes one or more transducers or speakers powered byone or more amplifiers. In other embodiments, however, a playback deviceincludes one of (or neither of) the speaker and the amplifier. Forinstance, a playback device can comprise one or more amplifiersconfigured to drive one or more speakers external to the playback devicevia a corresponding wire or cable.

Moreover, as used herein the term NMD (i.e., a “network microphonedevice”) can generally refer to a network device that is configured foraudio detection. In some embodiments, an NMD is a stand-alone deviceconfigured primarily for audio detection. In other embodiments, an NMDis incorporated into a playback device (or vice versa).

The term “control device” can generally refer to a network deviceconfigured to perform functions relevant to facilitating user access,control, and/or configuration of the media playback system 100.

Each of the playback devices 110 is configured to receive audio signalsor data from one or more media sources (e.g., one or more remoteservers, one or more local devices) and play back the received audiosignals or data as sound. The one or more NMDs 120 are configured toreceive spoken word commands, and the one or more control devices 130are configured to receive user input. In response to the received spokenword commands and/or user input, the media playback system 100 can playback audio via one or more of the playback devices 110. In certainembodiments, the playback devices 110 are configured to commenceplayback of media content in response to a trigger. For instance, one ormore of the playback devices 110 can be configured to play back amorning playlist upon detection of an associated trigger condition(e.g., presence of a user in a kitchen, detection of a coffee machineoperation). In some embodiments, for example, the media playback system100 is configured to play back audio from a first playback device (e.g.,the playback device 100 a) in synchrony with a second playback device(e.g., the playback device 100 b). Interactions between the playbackdevices 110, NMDs 120, and/or control devices 130 of the media playbacksystem 100 configured in accordance with the various embodiments of thedisclosure are described in greater detail below with respect to FIGS.1B-6 .

In the illustrated embodiment of FIG. 1A, the environment 101 includes ahousehold having several rooms, spaces, and/or playback zones, including(clockwise from upper left) a master bathroom 101 a, a master bedroom101 b, a second bedroom 101 c, a family room or den 101 d, an office 101e, a living room 101 f, a dining room 101 g, a kitchen 101 h, and anoutdoor patio 101 i. While certain embodiments and examples aredescribed below in the context of a home environment, the technologiesdescribed herein may be implemented in other types of environments. Insome embodiments, for example, the media playback system 100 can beimplemented in one or more commercial settings (e.g., a restaurant,mall, airport, hotel, a retail or other store), one or more vehicles(e.g., a sports utility vehicle, bus, car, a ship, a boat, an airplane),multiple environments (e.g., a combination of home and vehicleenvironments), and/or another suitable environment where multi-zoneaudio may be desirable.

The media playback system 100 can comprise one or more playback zones,some of which may correspond to the rooms in the environment 101. Themedia playback system 100 can be established with one or more playbackzones, after which additional zones may be added, or removed to form,for example, the configuration shown in FIG. 1A. Each zone may be givena name according to a different room or space such as the office 101 e,master bathroom 101 a, master bedroom 101 b, the second bedroom 101 c,kitchen 101 h, dining room 101 g, living room 101 f, and/or the balcony101 i. In some aspects, a single playback zone may include multiplerooms or spaces. In certain aspects, a single room or space may includemultiple playback zones.

In the illustrated embodiment of FIG. 1A, the master bathroom 101 a, thesecond bedroom 101 c, the office 101 e, the living room 101 f, thedining room 101 g, the kitchen 101 h, and the outdoor patio 101 i eachinclude one playback device 110, and the master bedroom 101 b and theden 101 d include a plurality of playback devices 110. In the masterbedroom 101 b, the playback devices 110 l and 110 m may be configured,for example, to play back audio content in synchrony as individual onesof playback devices 110, as a bonded playback zone, as a consolidatedplayback device, and/or any combination thereof. Similarly, in the den101 d, the playback devices 110 h-j can be configured, for instance, toplay back audio content in synchrony as individual ones of playbackdevices 110, as one or more bonded playback devices, and/or as one ormore consolidated playback devices. Additional details regarding bondedand consolidated playback devices are described below with respect toFIGS. 1B and 1E, as well as FIGS. 14-1M.

In some aspects, one or more of the playback zones in the environment101 may each be playing different audio content. For instance, a usermay be grilling on the patio 101 i and listening to hip hop music beingplayed by the playback device 110 c while another user is preparing foodin the kitchen 101 h and listening to classical music played by theplayback device 110 b. In another example, a playback zone may play thesame audio content in synchrony with another playback zone. Forinstance, the user may be in the office 101 e listening to the playbackdevice 110 f playing back the same hip hop music being played back byplayback device 110 c on the patio 101 i. In some aspects, the playbackdevices 110 c and 110 f play back the hip hop music in synchrony suchthat the user perceives that the audio content is being playedseamlessly (or at least substantially seamlessly) while moving betweendifferent playback zones.

a. Suitable Media Playback System

FIG. 1B is a schematic diagram of the media playback system 100 and acloud network 102. For ease of illustration, certain devices of themedia playback system 100 and the cloud network 102 are omitted fromFIG. 1B. One or more communication links 103 (referred to hereinafter as“the links 103”) communicatively couple the media playback system 100and the cloud network 102.

The links 103 can comprise, for example, one or more wired networks, oneor more wireless networks, one or more wide area networks (WAN), one ormore local area networks (LAN), one or more personal area networks(PAN), one or more telecommunication networks (e.g., one or more GlobalSystem for Mobiles (GSM) networks, Code Division Multiple Access (CDMA)networks, Long-Term Evolution (LTE) networks, 5G communication networknetworks, and/or other suitable data transmission protocol networks),etc. The cloud network 102 is configured to deliver media content (e.g.,audio content, video content, photographs, social media content) to themedia playback system 100 in response to a request transmitted from themedia playback system 100 via the links 103. In some embodiments, thecloud network 102 is further configured to receive data (e.g. voiceinput data) from the media playback system 100 and correspondinglytransmit commands and/or media content to the media playback system 100.

The cloud network 102 includes computing devices 106 (identifiedseparately as a first computing device 106 a, a second computing device106 b, and a third computing device 106 c). The computing devices 106can comprise individual computers or servers, such as, for example, amedia streaming service server storing audio and/or other media content,a voice service server, a social media server, a media playback systemcontrol server, etc. In some embodiments, one or more of the computingdevices 106 comprise modules of a single computer or server. In certainembodiments, one or more of the computing devices 106 comprise one ormore modules, computers, and/or servers. Moreover, while the cloudnetwork 102 is described above in the context of a single cloud network,in some embodiments the cloud network 102 includes a plurality of cloudnetworks comprising communicatively coupled computing devices.Furthermore, while the cloud network 102 is shown in FIG. 1B as havingthree of the computing devices 106, in some embodiments, the cloudnetwork 102 includes fewer (or more than) three computing devices 106.

The media playback system 100 is configured to receive media contentfrom the networks 102 via the links 103. The received media content cancomprise, for example, a Uniform Resource Identifier (URI) and/or aUniform Resource Locator (URL). For instance, in some examples, themedia playback system 100 can stream, download, or otherwise obtain datafrom a URI or a URL corresponding to the received media content. Anetwork 104 communicatively couples the links 103 and at least a portionof the devices (e.g., one or more of the playback devices 110, NMDs 120,and/or control devices 130) of the media playback system 100. Thenetwork 104 can include, for example, a wireless network (e.g., a WiFinetwork, a Bluetooth, a Z-Wave network, a ZigBee, and/or other suitablewireless communication protocol network) and/or a wired network (e.g., anetwork comprising Ethernet, Universal Serial Bus (USB), and/or anothersuitable wired communication). As those of ordinary skill in the artwill appreciate, as used herein, “WiFi” can refer to several differentcommunication protocols including, for example, Institute of Electricaland Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.11ac, 802.11ad, 802.11af, 802.11ah, 802.11ai, 802.11aj,802.11aq, 802.11ax, 802.11ay, 802.15, etc. transmitted at 2.4 Gigahertz(GHz), 5 GHz, and/or another suitable frequency.

In some embodiments, the network 104 includes a dedicated communicationnetwork that the media playback system 100 uses to transmit messagesbetween individual devices and/or to transmit media content to and frommedia content sources (e.g., one or more of the computing devices 106).In certain embodiments, the network 104 is configured to be accessibleonly to devices in the media playback system 100, thereby reducinginterference and competition with other household devices. In someexamples, the dedicated communication network is implemented as a meshnetwork where the devices in the media playback system form the nodes inthe mesh network. One or more root nodes of the mesh network thenconnect the mesh network to a household WiFi network, which functions inparallel to the mesh network.

In other embodiments, however, the network 104 includes an existinghousehold communication network (e.g., a household WiFi network). Insome embodiments, the links 103 and the network 104 comprise one or moreof the same networks. In some aspects, for example, the links 103 andthe network 104 comprise a telecommunication network (e.g., an LTEnetwork, a 5G network). Moreover, in some embodiments, the mediaplayback system 100 is implemented without the network 104, and devicescomprising the media playback system 100 can communicate with eachother, for example, via one or more direct connections, PANs,telecommunication networks, and/or other suitable communication links.

In some embodiments, audio content sources may be regularly added orremoved from the media playback system 100. In some embodiments, forexample, the media playback system 100 performs an indexing of mediaitems when one or more media content sources are updated, added to,and/or removed from the media playback system 100. The media playbacksystem 100 can scan identifiable media items in some or all foldersand/or directories accessible to the playback devices 110, and generateor update a media content database comprising metadata (e.g., title,artist, album, track length) and other associated information (e.g.,URIs, URLs) for each identifiable media item found. In some embodiments,for example, the media content database is stored on one or more of theplayback devices 110, network microphone devices 120, and/or controldevices 130.

In the illustrated embodiment of FIG. 1B, the playback devices 110 l and110 m comprise a group 107 a. The playback devices 110 l and 110 m canbe positioned in different rooms in a household and be grouped togetherin the group 107 a on a temporary or permanent basis based on user inputreceived at the control device 130 a and/or another control device 130in the media playback system 100. When arranged in the group 107 a, theplayback devices 110 l and 110 m can be configured to play back the sameor similar audio content in synchrony from one or more audio contentsources. In certain embodiments, for example, the group 107 a includes abonded zone in which the playback devices 110 l and 110 m comprise leftaudio and right audio channels, respectively, of multi-channel audiocontent, thereby producing or enhancing a stereo effect of the audiocontent. In some embodiments, the group 107 a includes additionalplayback devices 110. In other embodiments, however, the media playbacksystem 100 omits the group 107 a and/or other grouped arrangements ofthe playback devices 110. Additional details regarding groups and otherarrangements of playback devices are described in further detail belowwith respect to FIGS. 1 -I through IM.

The media playback system 100 includes the NMDs 120 a and 120 d, eachcomprising one or more microphones configured to receive voiceutterances from a user. In the illustrated embodiment of FIG. 1B, theNMD 120 a is a standalone device and the NMD 120 d is integrated intothe playback device 110 n. The NMD 120 a, for example, is configured toreceive voice input 121 from a user 123. In some embodiments, the NMD120 a transmits data associated with the received voice input 121 to avoice assistant service (VAS) configured to (i) process the receivedvoice input data and (ii) transmit a corresponding command to the mediaplayback system 100. In some aspects, for example, the computing device106 c includes one or more modules and/or servers of a VAS (e.g., a VASoperated by one or more of SONOS®, AMAZON®, GOOGLE® APPLE®, MICROSOFT®).The computing device 106 c can receive the voice input data from the NMD120 a via the network 104 and the links 103. In response to receivingthe voice input data, the computing device 106 c processes the voiceinput data (i.e., “Play Hey Jude by The Beatles”), and determines thatthe processed voice input includes a command to play a song (e.g., “HeyJude”). The computing device 106 c accordingly transmits commands to themedia playback system 100 to play back “Hey Jude” by the Beatles from asuitable media service (e.g., via one or more of the computing devices106) on one or more of the playback devices 110.

b. Suitable Playback Devices

FIG. 1C is a block diagram of the playback device 110 a comprising aninput/output 111. The input/output 111 can include an analog I/O 111 a(e.g., one or more wires, cables, and/or other suitable communicationlinks configured to carry analog signals) and/or a digital I/O 111 b(e.g., one or more wires, cables, or other suitable communication linksconfigured to carry digital signals). In some embodiments, the analogI/O 111 a is an audio line-in input connection comprising, for example,an auto-detecting 3.5 mm audio line-in connection. In some embodiments,the digital I/O 111 b includes a Sony/Philips Digital Interface Format(S/PDIF) communication interface and/or cable and/or a Toshiba Link(TOSLINK) cable. In some embodiments, the digital I/O 111 b includes anHigh-Definition Multimedia Interface (HDMI) interface and/or cable. Insome embodiments, the digital I/O 111 b includes one or more wirelesscommunication links comprising, for example, a radio frequency (RF),infrared, WiFi, Bluetooth, or another suitable communication protocol.In certain embodiments, the analog I/O 111 a and the digital 111 bcomprise interfaces (e.g., ports, plugs, jacks) configured to receiveconnectors of cables transmitting analog and digital signals,respectively, without necessarily including cables.

The playback device 110 a, for example, can receive media content (e.g.,audio content comprising music and/or other sounds) from a local audiosource 105 via the input/output 111 (e.g., a cable, a wire, a PAN, aBluetooth connection, an ad hoc wired or wireless communication network,and/or another suitable communication link). The local audio source 105can comprise, for example, a mobile device (e.g., a smartphone, atablet, a laptop computer) or another suitable audio component (e.g., atelevision, a desktop computer, an amplifier, a phonograph, a Blu-rayplayer, a memory storing digital media files). In some aspects, thelocal audio source 105 includes local music libraries on a smartphone, acomputer, a networked-attached storage (NAS), and/or another suitabledevice configured to store media files. In certain embodiments, one ormore of the playback devices 110, NMDs 120, and/or control devices 130comprise the local audio source 105. In other embodiments, however, themedia playback system omits the local audio source 105 altogether. Insome embodiments, the playback device 110 a does not include aninput/output 111 and receives all audio content via the network 104.

The playback device 110 a further includes electronics 112, a userinterface 113 (e.g., one or more buttons, knobs, dials, touch-sensitivesurfaces, displays, touchscreens), and one or more transducers 114(referred to hereinafter as “the transducers 114”). The electronics 112is configured to receive audio from an audio source (e.g., the localaudio source 105) via the input/output 111, one or more of the computingdevices 106 a-c via the network 104 (FIG. 1B)), amplify the receivedaudio, and output the amplified audio for playback via one or more ofthe transducers 114. In some embodiments, the playback device 110 aoptionally includes one or more microphones 115 (e.g., a singlemicrophone, a plurality of microphones, a microphone array) (hereinafterreferred to as “the microphones 115”). In certain embodiments, forexample, the playback device 110 a having one or more of the optionalmicrophones 115 can operate as an NMD configured to receive voice inputfrom a user and correspondingly perform one or more operations based onthe received voice input.

In the illustrated embodiment of FIG. 1C, the electronics 112 compriseone or more processors 112 a (referred to hereinafter as “the processors112 a”), memory 112 b, software components 112 c, a network interface112 d, one or more audio processing components 112 g (referred tohereinafter as “the audio components 112 g”), one or more audioamplifiers 112 h (referred to hereinafter as “the amplifiers 112 h”),and power 112 i (e.g., one or more power supplies, power cables, powerreceptacles, batteries, induction coils, Power-over Ethernet (POE)interfaces, and/or other suitable sources of electric power). In someembodiments, the electronics 112 optionally include one or more othercomponents 112 j (e.g., one or more sensors, video displays,touchscreens).

The processors 112 a can comprise clock-driven computing component(s)configured to process data, and the memory 112 b can comprise acomputer-readable medium (e.g., a tangible, non-transitorycomputer-readable medium, data storage loaded with one or more of thesoftware components 112 c) configured to store instructions forperforming various operations and/or functions. The processors 112 a areconfigured to execute the instructions stored on the memory 112 b toperform one or more of the operations. The operations can include, forexample, causing the playback device 110 a to retrieve audio data froman audio source (e.g., one or more of the computing devices 106 a-c(FIG. 1B)), and/or another one of the playback devices 110. In someembodiments, the operations further include causing the playback device110 a to send audio data to another one of the playback devices 110 aand/or another device (e.g., one of the NMDs 120). Certain embodimentsinclude operations causing the playback device 110 a to pair withanother of the one or more playback devices 110 to enable amulti-channel audio environment (e.g., a stereo pair, a bonded zone).

The processors 112 a can be further configured to perform operationscausing the playback device 110 a to synchronize playback of audiocontent with another of the one or more playback devices 110. As thoseof ordinary skill in the art will appreciate, during synchronousplayback of audio content on a plurality of playback devices, a listenerwill preferably be unable to perceive time-delay differences betweenplayback of the audio content by the playback device 110 a and the otherone or more other playback devices 110. Additional details regardingaudio playback synchronization among playback devices can be found, forexample, in U.S. Pat. No. 8,234,395, which was incorporated by referenceabove.

In some embodiments, the memory 112 b is further configured to storedata associated with the playback device 110 a, such as one or morezones and/or zone groups of which the playback device 110 a is a member,audio sources accessible to the playback device 110 a, and/or a playbackqueue that the playback device 110 a (and/or another of the one or moreplayback devices) can be associated with. The stored data can compriseone or more state variables that are periodically updated and used todescribe a state of the playback device 110 a. The memory 112 b can alsoinclude data associated with a state of one or more of the other devices(e.g., the playback devices 110, NMDs 120, control devices 130) of themedia playback system 100. In some aspects, for example, the state datais shared during predetermined intervals of time (e.g., every 5 seconds,every 10 seconds, every 60 seconds) among at least a portion of thedevices of the media playback system 100, so that one or more of thedevices have the most recent data associated with the media playbacksystem 100.

The network interface 112 d is configured to facilitate a transmissionof data between the playback device 110 a and one or more other deviceson a data network such as, for example, the links 103 and/or the network104 (FIG. 1B). The network interface 112 d is configured to transmit andreceive data corresponding to media content (e.g., audio content, videocontent, text, photographs) and other signals (e.g., non-transitorysignals) comprising digital packet data including an Internet Protocol(IP)-based source address and/or an IP-based destination address. Thenetwork interface 112 d can parse the digital packet data such that theelectronics 112 properly receives and processes the data destined forthe playback device 110 a.

In the illustrated embodiment of FIG. 1C, the network interface 112 dincludes one or more wireless interfaces 112 e (referred to hereinafteras “the wireless interface 112 e”). The wireless interface 112 e (e.g.,a suitable interface comprising one or more antennae) can be configuredto wirelessly communicate with one or more other devices (e.g., one ormore of the other playback devices 110, NMDs 120, and/or control devices130) that are communicatively coupled to the network 104 (FIG. 1B) inaccordance with a suitable wireless communication protocol (e.g., WiFi,Bluetooth, LTE). In some embodiments, the network interface 112 doptionally includes a wired interface 112 f (e.g., an interface orreceptacle configured to receive a network cable such as an Ethernet, aUSB-A, USB-C, and/or Thunderbolt cable) configured to communicate over awired connection with other devices in accordance with a suitable wiredcommunication protocol. In certain embodiments, the network interface112 d includes the wired interface 112 f and excludes the wirelessinterface 112 e. In some embodiments, the electronics 112 excludes thenetwork interface 112 d altogether and transmits and receives mediacontent and/or other data via another communication path (e.g., theinput/output 111).

The audio components 112 g are configured to process and/or filter datacomprising media content received by the electronics 112 (e.g., via theinput/output 111 and/or the network interface 112 d) to produce outputaudio signals. In some embodiments, the audio processing components 112g comprise, for example, one or more digital-to-analog converters (DAC),audio preprocessing components, audio enhancement components, a digitalsignal processors (DSPs), and/or other suitable audio processingcomponents, modules, circuits, etc. In certain embodiments, one or moreof the audio processing components 112 g can comprise one or moresubcomponents of the processors 112 a. In some embodiments, theelectronics 112 omits the audio processing components 112 g. In someaspects, for example, the processors 112 a execute instructions storedon the memory 112 b to perform audio processing operations to producethe output audio signals.

The amplifiers 112 h are configured to receive and amplify the audiooutput signals produced by the audio processing components 112 g and/orthe processors 112 a. The amplifiers 112 h can comprise electronicdevices and/or components configured to amplify audio signals to levelssufficient for driving one or more of the transducers 114. In someembodiments, for example, the amplifiers 112 h include one or moreswitching or class-D power amplifiers. In other embodiments, however,the amplifiers include one or more other types of power amplifiers(e.g., linear gain power amplifiers, class-A amplifiers, class-Bamplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers,class-E amplifiers, class-F amplifiers, class-G and/or class Hamplifiers, and/or another suitable type of power amplifier). In certainembodiments, the amplifiers 112 h comprise a suitable combination of twoor more of the foregoing types of power amplifiers. Moreover, in someembodiments, individual ones of the amplifiers 112 h correspond toindividual ones of the transducers 114. In other embodiments, however,the electronics 112 includes a single one of the amplifiers 112 hconfigured to output amplified audio signals to a plurality of thetransducers 114. In some other embodiments, the electronics 112 omitsthe amplifiers 112 h.

The transducers 114 (e.g., one or more speakers and/or speaker drivers)receive the amplified audio signals from the amplifier 112 h and renderor output the amplified audio signals as sound (e.g., audible soundwaves having a frequency between about 20 Hertz (Hz) and 20 kilohertz(kHz)). In some embodiments, the transducers 114 can comprise a singletransducer. In other embodiments, however, the transducers 114 comprisea plurality of audio transducers. In some embodiments, the transducers114 comprise more than one type of transducer. For example, thetransducers 114 can include one or more low frequency transducers (e.g.,subwoofers, woofers), mid-range frequency transducers (e.g., mid-rangetransducers, mid-woofers), and one or more high frequency transducers(e.g., one or more tweeters). As used herein, “low frequency” cangenerally refer to audible frequencies below about 500 Hz, “mid-rangefrequency” can generally refer to audible frequencies between about 500Hz and about 2 kHz, and “high frequency” can generally refer to audiblefrequencies above 2 kHz. In certain embodiments, however, one or more ofthe transducers 114 comprise transducers that do not adhere to theforegoing frequency ranges. For example, one of the transducers 114 maycomprise a mid-woofer transducer configured to output sound atfrequencies between about 200 Hz and about 5 kHz.

By way of illustration, SONOS, Inc. presently offers (or has offered)for sale certain playback devices including, for example, a “SONOS ONE,”“PLAY:1,” “PLAY:3,” “PLAY:5,” “PLAYBAR,” “PLAYBASE,” “CONNECT:AMP,”“CONNECT,” and “SUB.” Other suitable playback devices may additionallyor alternatively be used to implement the playback devices of exampleembodiments disclosed herein. Additionally, one of ordinary skilled inthe art will appreciate that a playback device is not limited to theexamples described herein or to SONOS product offerings. In someembodiments, for example, one or more playback devices 110 includeswired or wireless headphones (e.g., over-the-ear headphones, on-earheadphones, in-ear earphones). In other embodiments, one or more of theplayback devices 110 comprise a docking station and/or an interfaceconfigured to interact with a docking station for personal mobile mediaplayback devices. In certain embodiments, a playback device may beintegral to another device or component such as a television, a lightingfixture, or some other device for indoor or outdoor use. In someembodiments, a playback device omits a user interface and/or one or moretransducers. For example, FIG. 1D is a block diagram of a playbackdevice 110 p comprising the input/output 111 and electronics 112 withoutthe user interface 113 or transducers 114.

FIG. 1E is a block diagram of a bonded playback device 110 q comprisingthe playback device 110 a (FIG. 1C) sonically bonded with the playbackdevice 110 i (e.g., a subwoofer) (FIG. 1A). In the illustratedembodiment, the playback devices 110 a and 110 i are separate ones ofthe playback devices 110 housed in separate enclosures. In someembodiments, however, the bonded playback device 110 q includes a singleenclosure housing both the playback devices 110 a and 110 i. The bondedplayback device 110 q can be configured to process and reproduce sounddifferently than an unbonded playback device (e.g., the playback device110 a of FIG. 1C) and/or paired or bonded playback devices (e.g., theplayback devices 110 l and 110 m of FIG. 1B). In some embodiments, forexample, the playback device 110 a is full-range playback deviceconfigured to render low frequency, mid-range frequency, and highfrequency audio content, and the playback device 110 i is a subwooferconfigured to render low frequency audio content. In some aspects, theplayback device 110 a, when bonded with the first playback device, isconfigured to render only the mid-range and high frequency components ofa particular audio content, while the playback device 110 i renders thelow frequency component of the particular audio content. In someembodiments, the bonded playback device 110 q includes additionalplayback devices and/or another bonded playback device. Additionalplayback device embodiments are described in further detail below withrespect to FIGS. 2A-3D.

c. Suitable Network Microphone Devices (NMDs)

FIG. 1F is a block diagram of the NMD 120 a (FIGS. 1A and 1B). The NMD120 a includes one or more voice processing components 124 (hereinafter“the voice components 124”) and several components described withrespect to the playback device 110 a (FIG. 1C) including the processors112 a, the memory 112 b, and the microphones 115. The NMD 120 aoptionally includes other components also included in the playbackdevice 110 a (FIG. 1C), such as the user interface 113 and/or thetransducers 114. In some embodiments, the NMD 120 a is configured as amedia playback device (e.g., one or more of the playback devices 110),and further includes, for example, one or more of the audio components112 g (FIG. 1C), the amplifiers 114, and/or other playback devicecomponents. In certain embodiments, the NMD 120 a includes an Internetof Things (IoT) device such as, for example, a thermostat, alarm panel,fire and/or smoke detector, etc. In some embodiments, the NMD 120 aincludes the microphones 115, the voice processing 124, and only aportion of the components of the electronics 112 described above withrespect to FIG. 1B. In some aspects, for example, the NMD 120 a includesthe processor 112 a and the memory 112 b (FIG. 1B), while omitting oneor more other components of the electronics 112. In some embodiments,the NMD 120 a includes additional components (e.g., one or more sensors,cameras, thermometers, barometers, hygrometers).

In some embodiments, an NMD can be integrated into a playback device.FIG. 1G is a block diagram of a playback device 110 r comprising an NMD120 d. The playback device 110 r can comprise many or all of thecomponents of the playback device 110 a and further include themicrophones 115 and voice processing 124 (FIG. 1F). The playback device110 r optionally includes an integrated control device 130 c. Thecontrol device 130 c can comprise, for example, a user interface (e.g.,the user interface 113 of FIG. 1B) configured to receive user input(e.g., touch input, voice input) without a separate control device. Inother embodiments, however, the playback device 110 r receives commandsfrom another control device (e.g., the control device 130 a of FIG. 1B).

Referring again to FIG. 1F, the microphones 115 are configured toacquire, capture, and/or receive sound from an environment (e.g., theenvironment 101 of FIG. 1A) and/or a room in which the NMD 120 a ispositioned. The received sound can include, for example, vocalutterances, audio played back by the NMD 120 a and/or another playbackdevice, background voices, ambient sounds, etc. The microphones 115convert the received sound into electrical signals to produce microphonedata. The voice processing 124 receives and analyzes the microphone datato determine whether a voice input is present in the microphone data.The voice input can comprise, for example, an activation word followedby an utterance including a user request. As those of ordinary skill inthe art will appreciate, an activation word is a word or other audio cuethat signifying a user voice input. For instance, in querying theAMAZON® VAS, a user might speak the activation word “Alexa.” Otherexamples include “Ok, Google” for invoking the GOOGLE® VAS and “Hey,Siri” for invoking the APPLE® VAS.

After detecting the activation word, voice processing 124 monitors themicrophone data for an accompanying user request in the voice input. Theuser request may include, for example, a command to control athird-party device, such as a thermostat (e.g., NEST® thermostat), anillumination device (e.g., a PHILIPS HUE® lighting device), or a mediaplayback device (e.g., a Sonos® playback device). For example, a usermight speak the activation word “Alexa” followed by the utterance “setthe thermostat to 68 degrees” to set a temperature in a home (e.g., theenvironment 101 of FIG. 1A). The user might speak the same activationword followed by the utterance “turn on the living room” to turn onillumination devices in a living room area of the home. The user maysimilarly speak an activation word followed by a request to play aparticular song, an album, or a playlist of music on a playback devicein the home. Additional description regarding receiving and processingvoice input data can be found in further detail below with respect toFIGS. 3A-3F.

d. Suitable Control Devices

FIG. 1H is a partially schematic diagram of the control device 130 a(FIGS. 1A and 1B). As used herein, the term “control device” can be usedinterchangeably with “controller” or “control system.” Among otherfeatures, the control device 130 a is configured to receive user inputrelated to the media playback system 100 and, in response, cause one ormore devices in the media playback system 100 to perform an action(s) oroperation(s) corresponding to the user input. In the illustratedembodiment, the control device 130 a includes a smartphone (e.g., aniPhone™, an Android phone) on which media playback system controllerapplication software is installed. In some embodiments, the controldevice 130 a includes, for example, a tablet (e.g., an iPad™), acomputer (e.g., a laptop computer, a desktop computer), and/or anothersuitable device (e.g., a television, an automobile audio head unit, anIoT device). In certain embodiments, the control device 130 a includes adedicated controller for the media playback system 100. In otherembodiments, as described above with respect to FIG. 1G, the controldevice 130 a is integrated into another device in the media playbacksystem 100 (e.g., one more of the playback devices 110, NMDs 120, and/orother suitable devices configured to communicate over a network).

The control device 130 a includes electronics 132, a user interface 133,one or more speakers 134, and one or more microphones 135. Theelectronics 132 comprise one or more processors 132 a (referred tohereinafter as “the processors 132 a”), a memory 132 b, softwarecomponents 132 c, and a network interface 132 d. The processor 132 a canbe configured to perform functions relevant to facilitating user access,control, and configuration of the media playback system 100. The memory132 b can comprise data storage that can be loaded with one or more ofthe software components executable by the processor 302 to perform thosefunctions. The software components 132 c can comprise applicationsand/or other executable software configured to facilitate control of themedia playback system 100. The memory 112 b can be configured to store,for example, the software components 132 c, media playback systemcontroller application software, and/or other data associated with themedia playback system 100 and the user.

The network interface 132 d is configured to facilitate networkcommunications between the control device 130 a and one or more otherdevices in the media playback system 100, and/or one or more remotedevices. In some embodiments, the network interface 132 is configured tooperate according to one or more suitable communication industrystandards (e.g., infrared, radio, wired standards including IEEE 802.3,wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.15, 4G, LTE). The network interface 132 d can beconfigured, for example, to transmit data to and/or receive data fromthe playback devices 110, the NMDs 120, other ones of the controldevices 130, one of the computing devices 106 of FIG. 1B, devicescomprising one or more other media playback systems, etc. Thetransmitted and/or received data can include, for example, playbackdevice control commands, state variables, playback zone and/or zonegroup configurations. For instance, based on user input received at theuser interface 133, the network interface 132 d can transmit a playbackdevice control command (e.g., volume control, audio playback control,audio content selection) from the control device 304 to one or more ofthe playback devices 100. The network interface 132 d can also transmitand/or receive configuration changes such as, for example,adding/removing one or more playback devices 100 to/from a zone,adding/removing one or more zones to/from a zone group, forming a bondedor consolidated player, separating one or more playback devices from abonded or consolidated player, among others. Additional description ofzones and groups can be found below with respect to FIGS. 1 -I through1M.

The user interface 133 is configured to receive user input and canfacilitate ‘control of the media playback system 100. The user interface133 includes media content art 133 a (e.g., album art, lyrics, videos),a playback status indicator 133 b (e.g., an elapsed and/or remainingtime indicator), media content information region 133 c, a playbackcontrol region 133 d, and a zone indicator 133 e. The media contentinformation region 133 c can include a display of relevant information(e.g., title, artist, album, genre, release year) about media contentcurrently playing and/or media content in a queue or playlist. Theplayback control region 133 d can include selectable (e.g., via touchinput and/or via a cursor or another suitable selector) icons to causeone or more playback devices in a selected playback zone or zone groupto perform playback actions such as, for example, play or pause, fastforward, rewind, skip to next, skip to previous, enter/exit shufflemode, enter/exit repeat mode, enter/exit cross fade mode, etc. Theplayback control region 133 d may also include selectable icons tomodify equalization settings, playback volume, and/or other suitableplayback actions. In the illustrated embodiment, the user interface 133includes a display presented on a touch screen interface of a smartphone(e.g., an iPhone™, an Android phone). In some embodiments, however, userinterfaces of varying formats, styles, and interactive sequences mayalternatively be implemented on one or more network devices to providecomparable control access to a media playback system.

The one or more speakers 134 (e.g., one or more transducers) can beconfigured to output sound to the user of the control device 130 a. Insome embodiments, the one or more speakers comprise individualtransducers configured to correspondingly output low frequencies,mid-range frequencies, and/or high frequencies. In some aspects, forexample, the control device 130 a is configured as a playback device(e.g., one of the playback devices 110). Similarly, in some embodimentsthe control device 130 a is configured as an NMD (e.g., one of the NMDs120), receiving voice commands and other sounds via the one or moremicrophones 135.

The one or more microphones 135 can comprise, for example, one or morecondenser microphones, electret condenser microphones, dynamicmicrophones, and/or other suitable types of microphones or transducers.In some embodiments, two or more of the microphones 135 are arranged tocapture location information of an audio source (e.g., voice, audiblesound) and/or configured to facilitate filtering of background noise.Moreover, in certain embodiments, the control device 130 a is configuredto operate as playback device and an NMD. In other embodiments, however,the control device 130 a omits the one or more speakers 134 and/or theone or more microphones 135. For instance, the control device 130 a maycomprise a device (e.g., a thermostat, an IoT device, a network device)comprising a portion of the electronics 132 and the user interface 133(e.g., a touch screen) without any speakers or microphones. Additionalcontrol device embodiments are described in further detail below withrespect to FIGS. 4A-4D and 5 .

e. Suitable Playback Device Configurations

FIGS. 1-1 through 1M show example configurations of playback devices inzones and zone groups. Referring first to FIG. 1M, in one example, asingle playback device may belong to a zone. For example, the playbackdevice 110 g in the second bedroom 101 c (FIG. 1A) may belong to Zone C.In some implementations described below, multiple playback devices maybe “bonded” to form a “bonded pair” which together form a single zone.For example, the playback device 110 l (e.g., a left playback device)can be bonded to the playback device 110 l (e.g., a left playbackdevice) to form Zone A. Bonded playback devices may have differentplayback responsibilities (e.g., channel responsibilities). In anotherimplementation described below, multiple playback devices may be mergedto form a single zone. For example, the playback device 110 h (e.g., afront playback device) may be merged with the playback device 110 i(e.g., a subwoofer), and the playback devices 110 j and 110 k (e.g.,left and right surround speakers, respectively) to form a single Zone D.In another example, the playback devices 110 g and 110 h can be bemerged to form a merged group or a zone group 108 b. The merged playbackdevices 110 g and 110 h may not be specifically assigned differentplayback responsibilities. That is, the merged playback devices 110 hand 110 i may, aside from playing audio content in synchrony, each playaudio content as they would if they were not merged.

Each zone in the media playback system 100 may be provided for controlas a single user interface (UI) entity. For example, Zone A may beprovided as a single entity named Master Bathroom. Zone B may beprovided as a single entity named Master Bedroom. Zone C may be providedas a single entity named Second Bedroom.

Playback devices that are bonded may have different playbackresponsibilities, such as responsibilities for certain audio channels.For example, as shown in FIG. 1 -I, the playback devices 110 l and 110 mmay be bonded so as to produce or enhance a stereo effect of audiocontent. In this example, the playback device 110 l may be configured toplay a left channel audio component, while the playback device 110 k maybe configured to play a right channel audio component. In someimplementations, such stereo bonding may be referred to as “pairing.”

Additionally, bonded playback devices may have additional and/ordifferent respective speaker drivers. As shown in FIG. 1J, the playbackdevice 110 h named Front may be bonded with the playback device 110 inamed SUB. The Front device 110 h can be configured to render a range ofmid to high frequencies and the SUB device 110 i can be configuredrender low frequencies. When unbonded, however, the Front device 110 hcan be configured render a full range of frequencies. As anotherexample, FIG. 1K shows the Front and SUB devices 110 h and 110 i furtherbonded with Left and Right playback devices 110 j and 110 k,respectively. In some implementations, the Right and Left devices 110 jand 102 k can be configured to form surround or “satellite” channels ofa home theater system. The bonded playback devices 110 h, 110 i, 110 j,and 110 k may form a single Zone D (FIG. 1M).

Playback devices that are merged may not have assigned playbackresponsibilities, and may each render the full range of audio contentthe respective playback device is capable of. Nevertheless, mergeddevices may be represented as a single UI entity (i.e., a zone, asdiscussed above). For instance, the playback devices 110 a and 110 n themaster bathroom have the single UI entity of Zone A. In one embodiment,the playback devices 110 a and 110 n may each output the full range ofaudio content each respective playback devices 110 a and 110 n arecapable of, in synchrony.

In some embodiments, an NMD is bonded or merged with another device soas to form a zone. For example, the NMD 120 b may be bonded with theplayback device 110 e, which together form Zone F, named Living Room. Inother embodiments, a stand-alone network microphone device may be in azone by itself. In other embodiments, however, a stand-alone networkmicrophone device may not be associated with a zone. Additional detailsregarding associating network microphone devices and playback devices asdesignated or default devices may be found, for example, in previouslyreferenced U.S. patent application Ser. No. 15/438,749.

Zones of individual, bonded, and/or merged devices may be grouped toform a zone group. For example, referring to FIG. 1M, Zone A may begrouped with Zone B to form a zone group 108 a that includes the twozones. Similarly, Zone G may be grouped with Zone H to form the zonegroup 108 b. As another example, Zone A may be grouped with one or moreother Zones C-I. The Zones A-I may be grouped and ungrouped in numerousways. For example, three, four, five, or more (e.g., all) of the ZonesA-I may be grouped. When grouped, the zones of individual and/or bondedplayback devices may play back audio in synchrony with one another, asdescribed in previously referenced U.S. Pat. No. 8,234,395. Playbackdevices may be dynamically grouped and ungrouped to form new ordifferent groups that synchronously play back audio content.

In various implementations, the zones in an environment may be thedefault name of a zone within the group or a combination of the names ofthe zones within a zone group. For example, Zone Group 108 b can have beassigned a name such as “Dining+Kitchen”, as shown in FIG. 1M. In someembodiments, a zone group may be given a unique name selected by a user.

Certain data may be stored in a memory of a playback device (e.g., thememory 112 c of FIG. 1C) as one or more state variables that areperiodically updated and used to describe the state of a playback zone,the playback device(s), and/or a zone group associated therewith. Thememory may also include the data associated with the state of the otherdevices of the media system, and shared from time to time among thedevices so that one or more of the devices have the most recent dataassociated with the system.

In some embodiments, the memory may store instances of various variabletypes associated with the states. Variables instances may be stored withidentifiers (e.g., tags) corresponding to type. For example, certainidentifiers may be a first type “a1” to identify playback device(s) of azone, a second type “b1” to identify playback device(s) that may bebonded in the zone, and a third type “c1” to identify a zone group towhich the zone may belong. As a related example, identifiers associatedwith the second bedroom 101 c may indicate that the playback device isthe only playback device of the Zone C and not in a zone group.Identifiers associated with the Den may indicate that the Den is notgrouped with other zones but includes bonded playback devices 110 h-110k. Identifiers associated with the Dining Room may indicate that theDining Room is part of the Dining+Kitchen zone group 108 b and thatdevices 110 b and 110 d are grouped (FIG. 1L). Identifiers associatedwith the Kitchen may indicate the same or similar information by virtueof the Kitchen being part of the Dining+Kitchen zone group 108 b. Otherexample zone variables and identifiers are described below.

In yet another example, the media playback system 100 may storevariables or identifiers representing other associations of zones andzone groups, such as identifiers associated with Areas, as shown in FIG.1M. An area may involve a cluster of zone groups and/or zones not withina zone group. For instance, FIG. 1M shows an Upper Area 109 a includingZones A-D, and a Lower Area 109 b including Zones E-I. In one aspect, anArea may be used to invoke a cluster of zone groups and/or zones thatshare one or more zones and/or zone groups of another cluster. Inanother aspect, this differs from a zone group, which does not share azone with another zone group. Further examples of techniques forimplementing Areas may be found, for example, in U.S. application Ser.No. 15/682,506 filed Aug. 21, 2017 and titled “Room Association Based onName,” and U.S. Pat. No. 8,483,853 filed Sep. 11, 2007, and titled“Controlling and manipulating groupings in a multi-zone media system.”Each of these applications is incorporated herein by reference in itsentirety. In some embodiments, the media playback system 100 might notimplement Areas, in which case the system may not store variablesassociated with Areas.

In further examples, the playback devices 110 of the media playbacksystem 100 are named and arranged according to a control hierarchyreferred to as home graph. Under the home graph hierarchy, the base unitof the home graph hierarchy is a “Set.” A “Set” refers to an individualdevice or multiple devices that operate together in performing a givenfunction, such as an individual playback device 110 or a bonded zone ofplayback devices. After Sets, the next level of the hierarchy is a“Room.” Under the home graph hierarchy, a “Room” can be considered acontainer for Sets in a given room of a home. For example, an exampleRoom might correspond to the kitchen of a home, and be assigned the name“Kitchen” and include one or more Sets (e.g. “Kitchen Island”). The nextlevel of the example home graph hierarchy is “Area,” which includes twoor more Rooms (e.g., “Upstairs” or “Downstairs”). The highest level ofthe home graph hierarchy is “Home.” A Home refers to the entire home,and all of the Sets within. Each level of the home graph hierarchy isassigned a human-readable name, which facilities control via GUI andVUI. Additional details regarding the home graph control hierarchy canbe found, for example, in U.S. patent application Ser. No. 16/216,357entitled, “Home Graph,” which is incorporated herein by reference in itsentirety.

III. Example Systems and Devices

FIG. 2A is a front isometric view of a playback device 210 configured inaccordance with aspects of the disclosed technology. FIG. 2B is a frontisometric view of the playback device 210 without a grille 216 e. FIG.2C is an exploded view of the playback device 210. Referring to FIGS.2A-2C together, the playback device 210 includes a housing 216 thatincludes an upper portion 216 a, a right or first side portion 216 b, alower portion 216 c, a left or second side portion 216 d, the grille 216e, and a rear portion 216 f. A plurality of fasteners 216 g (e.g., oneor more screws, rivets, clips) attaches a frame 216 h to the housing216. A cavity 216 j (FIG. 2C) in the housing 216 is configured toreceive the frame 216 h and electronics 212. The frame 216 h isconfigured to carry a plurality of transducers 214 (identifiedindividually in FIG. 2B as transducers 214 a-f). The electronics 212(e.g., the electronics 112 of FIG. 1C) is configured to receive audiocontent from an audio source and send electrical signals correspondingto the audio content to the transducers 214 for playback.

The transducers 214 are configured to receive the electrical signalsfrom the electronics 112, and further configured to convert the receivedelectrical signals into audible sound during playback. For instance, thetransducers 214 a-c (e.g., tweeters) can be configured to output highfrequency sound (e.g., sound waves having a frequency greater than about2 kHz). The transducers 214 d-f (e.g., mid-woofers, woofers, midrangespeakers) can be configured output sound at frequencies lower than thetransducers 214 a-c (e.g., sound waves having a frequency lower thanabout 2 kHz). In some embodiments, the playback device 210 includes anumber of transducers different than those illustrated in FIGS. 2A-2C.For example, the playback device 210 can include fewer than sixtransducers (e.g., one, two, three). In other embodiments, however, theplayback device 210 includes more than six transducers (e.g., nine,ten). Moreover, in some embodiments, all or a portion of the transducers214 are configured to operate as a phased array to desirably adjust(e.g., narrow or widen) a radiation pattern of the transducers 214,thereby altering a user's perception of the sound emitted from theplayback device 210.

In the illustrated embodiment of FIGS. 2A-2C, a filter 216 i is axiallyaligned with the transducer 214 b. The filter 216 i can be configured todesirably attenuate a predetermined range of frequencies that thetransducer 214 b outputs to improve sound quality and a perceived soundstage output collectively by the transducers 214. In some embodiments,however, the playback device 210 omits the filter 216 i. In otherembodiments, the playback device 210 includes one or more additionalfilters aligned with the transducers 214 b and/or at least another ofthe transducers 214.

FIGS. 3A and 3B are front and right isometric side views, respectively,of an NMD 320 configured in accordance with embodiments of the disclosedtechnology. FIG. 3C is an exploded view of the NMD 320. FIG. 3D is anenlarged view of a portion of FIG. 3B including a user interface 313 ofthe NMD 320. Referring first to FIGS. 3A-3C, the NMD 320 includes ahousing 316 comprising an upper portion 316 a, a lower portion 316 b andan intermediate portion 316 c (e.g., a grille). A plurality of ports,holes or apertures 316 d in the upper portion 316 a allow sound to passthrough to one or more microphones 315 (FIG. 3C) positioned within thehousing 316. The one or more microphones 316 are configured to receivedsound via the apertures 316 d and produce electrical signals based onthe received sound. In the illustrated embodiment, a frame 316 e (FIG.3C) of the housing 316 surrounds cavities 316 f and 316 g configured tohouse, respectively, a first transducer 314 a (e.g., a tweeter) and asecond transducer 314 b (e.g., a mid-woofer, a midrange speaker, awoofer). In other embodiments, however, the NMD 320 includes a singletransducer, or more than two (e.g., two, five, six) transducers. Incertain embodiments, the NMD 320 omits the transducers 314 a and 314 baltogether.

Electronics 312 (FIG. 3C) includes components configured to drive thetransducers 314 a and 314 b, and further configured to analyze audiodata corresponding to the electrical signals produced by the one or moremicrophones 315. In some embodiments, for example, the electronics 312comprises many or all of the components of the electronics 112 describedabove with respect to FIG. 1C. In certain embodiments, the electronics312 includes components described above with respect to FIG. 1F such as,for example, the one or more processors 112 a, the memory 112 b, thesoftware components 112 c, the network interface 112 d, etc. In someembodiments, the electronics 312 includes additional suitable components(e.g., proximity or other sensors).

Referring to FIG. 3D, the user interface 313 includes a plurality ofcontrol surfaces (e.g., buttons, knobs, capacitive surfaces) including afirst control surface 313 a (e.g., a previous control), a second controlsurface 313 b (e.g., a next control), and a third control surface 313 c(e.g., a play and/or pause control). A fourth control surface 313 d isconfigured to receive touch input corresponding to activation anddeactivation of the one or microphones 315. A first indicator 313 e(e.g., one or more light emitting diodes (LEDs) or another suitableilluminator) can be configured to illuminate only when the one or moremicrophones 315 are activated. A second indicator 313 f (e.g., one ormore LEDs) can be configured to remain solid during normal operation andto blink or otherwise change from solid to indicate a detection of voiceactivity. In some embodiments, the user interface 313 includesadditional or fewer control surfaces and illuminators. In oneembodiment, for example, the user interface 313 includes the firstindicator 313 e, omitting the second indicator 313 f. Moreover, incertain embodiments, the NMD 320 comprises a playback device and acontrol device, and the user interface 313 comprises the user interfaceof the control device.

Referring to FIGS. 3A-3D together, the NMD 320 is configured to receivevoice commands from one or more adjacent users via the one or moremicrophones 315. As described above with respect to FIG. 1B, the one ormore microphones 315 can acquire, capture, or record sound in a vicinity(e.g., a region within 10m or less of the NMD 320) and transmitelectrical signals corresponding to the recorded sound to theelectronics 312. The electronics 312 can process the electrical signalsand can analyze the resulting audio data to determine a presence of oneor more voice commands (e.g., one or more activation words). In someembodiments, for example, after detection of one or more suitable voicecommands, the NMD 320 is configured to transmit a portion of therecorded audio data to another device and/or a remote server (e.g., oneor more of the computing devices 106 of FIG. 1B) for further analysis.The remote server can analyze the audio data, determine an appropriateaction based on the voice command, and transmit a message to the NMD 320to perform the appropriate action. For instance, a user may speak“Sonos, play Michael Jackson.” The NMD 320 can, via the one or moremicrophones 315, record the user's voice utterance, determine thepresence of a voice command, and transmit the audio data having thevoice command to a remote server (e.g., one or more of the remotecomputing devices 106 of FIG. 1B, one or more servers of a VAS and/oranother suitable service). The remote server can analyze the audio dataand determine an action corresponding to the command. The remote servercan then transmit a command to the NMD 320 to perform the determinedaction (e.g., play back audio content related to Michael Jackson). TheNMD 320 can receive the command and play back the audio content relatedto Michael Jackson from a media content source. As described above withrespect to FIG. 1B, suitable content sources can include a device orstorage communicatively coupled to the NMD 320 via a LAN (e.g., thenetwork 104 of FIG. 1B), a remote server (e.g., one or more of theremote computing devices 106 of FIG. 1B), etc. In certain embodiments,however, the NMD 320 determines and/or performs one or more actionscorresponding to the one or more voice commands without intervention orinvolvement of an external device, computer, or server.

FIGS. 4A-4D are schematic diagrams of a control device 430 (e.g., thecontrol device 130 a of FIG. 1H, a smartphone, a tablet, a dedicatedcontrol device, an IoT device, and/or another suitable device) showingcorresponding user interface displays in various states of operation. Afirst user interface display 431 a (FIG. 4A) includes a display name 433a (i.e., “Rooms”). A selected group region 433 b displays audio contentinformation (e.g., artist name, track name, album art) of audio contentplayed back in the selected group and/or zone. Group regions 433 c and433 d display corresponding group and/or zone name, and audio contentinformation audio content played back or next in a playback queue of therespective group or zone. An audio content region 433 e includesinformation related to audio content in the selected group and/or zone(i.e., the group and/or zone indicated in the selected group region 433b). A lower display region 433 f is configured to receive touch input todisplay one or more other user interface displays. For example, if auser selects “Browse” in the lower display region 433 f, the controldevice 430 can be configured to output a second user interface display431 b (FIG. 4B) comprising a plurality of music services 433 g (e.g.,Spotify, Radio by Tunein, Apple Music, Pandora, Amazon, TV, local music,line-in) through which the user can browse and from which the user canselect media content for play back via one or more playback devices(e.g., one of the playback devices 110 of FIG. 1A). Alternatively, ifthe user selects “My Sonos” in the lower display region 433 f, thecontrol device 430 can be configured to output a third user interfacedisplay 431 c (FIG. 4C). A first media content region 433 h can includegraphical representations (e.g., album art) corresponding to individualalbums, stations, or playlists. A second media content region 433 i caninclude graphical representations (e.g., album art) corresponding toindividual songs, tracks, or other media content. If the user selectionsa graphical representation 433 j (FIG. 4C), the control device 430 canbe configured to begin play back of audio content corresponding to thegraphical representation 433 j and output a fourth user interfacedisplay 431 d fourth user interface display 431 d includes an enlargedversion of the graphical representation 433 j, media content information433 k (e.g., track name, artist, album), transport controls 433 m (e.g.,play, previous, next, pause, volume), and indication 433 n of thecurrently selected group and/or zone name.

FIG. 5 is a schematic diagram of a control device 530 (e.g., a laptopcomputer, a desktop computer). The control device 530 includestransducers 534, a microphone 535, and a camera 536. A user interface531 includes a transport control region 533 a, a playback status region533 b, a playback zone region 533 c, a playback queue region 533 d, anda media content source region 533 e. The transport control regionincludes one or more controls for controlling media playback including,for example, volume, previous, play/pause, next, repeat, shuffle, trackposition, crossfade, equalization, etc. The audio content source region533 e includes a listing of one or more media content sources from whicha user can select media items for play back and/or adding to a playbackqueue.

The playback zone region 533 b can include representations of playbackzones within the media playback system 100 (FIGS. 1A and 1B). In someembodiments, the graphical representations of playback zones may beselectable to bring up additional selectable icons to manage orconfigure the playback zones in the media playback system, such as acreation of bonded zones, creation of zone groups, separation of zonegroups, renaming of zone groups, etc. In the illustrated embodiment, a“group” icon is provided within each of the graphical representations ofplayback zones. The “group” icon provided within a graphicalrepresentation of a particular zone may be selectable to bring upoptions to select one or more other zones in the media playback systemto be grouped with the particular zone. Once grouped, playback devicesin the zones that have been grouped with the particular zone can beconfigured to play audio content in synchrony with the playbackdevice(s) in the particular zone. Analogously, a “group” icon may beprovided within a graphical representation of a zone group. In theillustrated embodiment, the “group” icon may be selectable to bring upoptions to deselect one or more zones in the zone group to be removedfrom the zone group. In some embodiments, the control device 530includes other interactions and implementations for grouping andungrouping zones via the user interface 531. In certain embodiments, therepresentations of playback zones in the playback zone region 533 b canbe dynamically updated as playback zone or zone group configurations aremodified.

The playback status region 533 c includes graphical representations ofaudio content that is presently being played, previously played, orscheduled to play next in the selected playback zone or zone group. Theselected playback zone or zone group may be visually distinguished onthe user interface, such as within the playback zone region 533 b and/orthe playback queue region 533 d. The graphical representations mayinclude track title, artist name, album name, album year, track length,and other relevant information that may be useful for the user to knowwhen controlling the media playback system 100 via the user interface531.

The playback queue region 533 d includes graphical representations ofaudio content in a playback queue associated with the selected playbackzone or zone group. In some embodiments, each playback zone or zonegroup may be associated with a playback queue containing informationcorresponding to zero or more audio items for playback by the playbackzone or zone group. For instance, each audio item in the playback queuemay comprise a uniform resource identifier (URI), a uniform resourcelocator (URL) or some other identifier that may be used by a playbackdevice in the playback zone or zone group to find and/or retrieve theaudio item from a local audio content source or a networked audiocontent source, possibly for playback by the playback device. In someembodiments, for example, a playlist can be added to a playback queue,in which information corresponding to each audio item in the playlistmay be added to the playback queue. In some embodiments, audio items ina playback queue may be saved as a playlist. In certain embodiments, aplayback queue may be empty, or populated but “not in use” when theplayback zone or zone group is playing continuously streaming audiocontent, such as Internet radio that may continue to play untilotherwise stopped, rather than discrete audio items that have playbackdurations. In some embodiments, a playback queue can include Internetradio and/or other streaming audio content items and be “in use” whenthe playback zone or zone group is playing those items.

When playback zones or zone groups are “grouped” or “ungrouped,”playback queues associated with the affected playback zones or zonegroups may be cleared or re-associated. For example, if a first playbackzone including a first playback queue is grouped with a second playbackzone including a second playback queue, the established zone group mayhave an associated playback queue that is initially empty, that containsaudio items from the first playback queue (such as if the secondplayback zone was added to the first playback zone), that contains audioitems from the second playback queue (such as if the first playback zonewas added to the second playback zone), or a combination of audio itemsfrom both the first and second playback queues. Subsequently, if theestablished zone group is ungrouped, the resulting first playback zonemay be re-associated with the previous first playback queue, or beassociated with a new playback queue that is empty or contains audioitems from the playback queue associated with the established zone groupbefore the established zone group was ungrouped. Similarly, theresulting second playback zone may be re-associated with the previoussecond playback queue, or be associated with a new playback queue thatis empty, or contains audio items from the playback queue associatedwith the established zone group before the established zone group wasungrouped.

FIG. 6 is a message flow diagram illustrating data exchanges betweendevices of the media playback system 100 (FIGS. 1A-1M).

At step 650 a, the media playback system 100 receives an indication ofselected media content (e.g., one or more songs, albums, playlists,podcasts, videos, stations) via the control device 130 a. The selectedmedia content can comprise, for example, media items stored locally onor more devices (e.g., the audio source 105 of FIG. 1C) connected to themedia playback system and/or media items stored on one or more mediaservice servers (one or more of the remote computing devices 106 of FIG.1B). In response to receiving the indication of the selected mediacontent, the control device 130 a transmits a message 651 a to theplayback device 110 a (FIGS. 1A-1C) to add the selected media content toa playback queue on the playback device 110 a.

At step 650 b, the playback device 110 a receives the message 651 a andadds the selected media content to the playback queue for play back.

At step 650 c, the control device 130 a receives input corresponding toa command to play back the selected media content. In response toreceiving the input corresponding to the command to play back theselected media content, the control device 130 a transmits a message 651b to the playback device 110 a causing the playback device 110 a to playback the selected media content. In response to receiving the message651 b, the playback device 110 a transmits a message 651 c to thecomputing device 106 a requesting the selected media content. Thecomputing device 106 a, in response to receiving the message 651 c,transmits a message 651 d comprising data (e.g., audio data, video data,a URL, a URI) corresponding to the requested media content.

At step 650 d, the playback device 110 a receives the message 651 d withthe data corresponding to the requested media content and plays back theassociated media content.

At step 650 e, the playback device 110 a optionally causes one or moreother devices to play back the selected media content. In one example,the playback device 110 a is one of a bonded zone of two or more players(FIG. 1M). The playback device 110 a can receive the selected mediacontent and transmit all or a portion of the media content to otherdevices in the bonded zone. In another example, the playback device 110a is a coordinator of a group and is configured to transmit and receivetiming information from one or more other devices in the group. Theother one or more devices in the group can receive the selected mediacontent from the computing device 106 a, and begin playback of theselected media content in response to a message from the playback device110 a such that all of the devices in the group play back the selectedmedia content in synchrony.

IV. Example Synchrony Grouping Techniques

Example synchrony techniques involve a group coordinator providing audiocontent and timing information to one or more group members tofacilitate synchronous playback among the group coordinator and thegroup members. In some embodiments, at least some aspects of thetechnical solutions derive from the technical structure and organizationof the audio information, playback timing, and clock timing informationthat the playback devices use to play audio content from audio sourcesin synchrony with each other, including how different playback devicesgenerate playback timing based on clock timing (local clock timing orremote clock timing) and play audio content based on playback timing(generated locally or remotely) and clock timing (generated locally orremotely). Therefore, to aid in understanding certain aspects of thedisclosed technical solutions, certain technical details of the audioinformation, playback timing, and clock timing information, as well ashow playback devices generate and/or use playback timing and clocktiming for playing audio content in different configurations, aredescribed below.

a. Audio Content

Audio content may be any type of audio content now known or laterdeveloped. For example, in some embodiments, the audio content includesany one or more of: (i) streaming music or other audio obtained from astreaming media service, such as Spotify, Pandora, or other streamingmedia services; (ii) streaming music or other audio from a local musiclibrary, such as a music library stored on a user's laptop computer,desktop computer, smartphone, tablet, home server, or other computingdevice now known or later developed; (iii) audio content associated withvideo content, such as audio associated with a television program ormovie received from any of a television, set-top box, Digital VideoRecorder, Digital Video Disc player, streaming video service, or anyother source of audio-visual media content now known or later developed;(iv) text-to-speech or other audible content from a voice assistantservice (VAS), such as Amazon Alexa or other VAS services now known orlater developed; (v) audio content from a doorbell or intercom systemsuch as Nest, Ring, or other doorbells or intercom systems now known orlater developed; and/or (vi) audio content from a telephone, videophone, video/teleconferencing system or other application configured toallow users to communicate with each other via audio and/or video.

In operation, a “sourcing” playback device obtains any of theaforementioned types of audio content from an audio source via aninterface on the playback device, e.g., one of the sourcing playbackdevice's network interfaces, a “line-in” analog interface, a digitalaudio interface, or any other interface suitable for receiving audiocontent in digital or analog format now known or later developed.

An audio source is any system, device, or application that generates,provides, or otherwise makes available any of the aforementioned audiocontent to a playback device. For example, in some embodiments, an audiosource includes any one or more of a streaming media (audio, video)service, digital media server or other computing system, VAS service,television, cable set-top-box, streaming media player (e.g., AppleTV,Roku, gaming console), CD/DVD player, doorbell, intercom, telephone,tablet, or any other source of digital audio content.

A playback device that receives or otherwise obtains audio content froman audio source for playback and/or distribution to other playbackdevices is sometimes referred to herein as the “sourcing” playbackdevice, “master” playback device, or “group coordinator.” One functionof the “sourcing” playback device is to process received audio contentfor playback and/or distribution to other playback devices. In someembodiments, the sourcing playback device transmits the processed audiocontent to all the playback devices that are configured to play theaudio content. In some embodiments, the sourcing playback devicetransmits the processed audio content to a multicast network address,and all the other playback devices configured to play the audio contentreceive the audio content via that multicast address. In someembodiments, the sourcing playback device alternatively transmits theprocessed audio content to each unicast network address of each otherplayback device configured to play the audio content, and each of theother playback devices configured to play the audio content receive theaudio content via its unicast address.

In some embodiments, the “sourcing” playback device receives audiocontent from an audio source in digital form, e.g., as a stream ofpackets. In some embodiments, individual packets in the stream ofpackets have a sequence number or other identifier that specifies anordering of the packets. Packets transmitted over a data packet network(e.g., Ethernet, WiFi, or other packet networks) may arrive out oforder, so the sourcing playback device uses the sequence number or otheridentifier to reassemble the stream of packets in the correct orderbefore performing further packet processing. In some embodiments, thesequence number or other identifier that specifies the ordering of thepackets is or at least comprises a timestamp indicating a time when thepacket was created. The packet creation time can be used as a sequencenumber based on an assumption that packets are created in the order inwhich they should be subsequently played out.

In some embodiments, the sourcing playback device does not change thesequence number or identifier of the received packets during packetprocessing. In some embodiments, the sourcing playback device reordersat least a first set packets in a packet stream based on each packet'ssequence identifier, extracts audio content from the received packets,reassembles a bitstream of audio content from the received packets, andthen repacketizes the reassembled bitstream into a second set ofpackets, where packets in the second set of packets have sequencenumbers that differ from the sequence numbers of the packets in thefirst set of packets. In some embodiments, individual packets in thesecond set of packets are a different length (i.e., shorter or longer)than individual packets in the first set of packets. In someembodiments, reassembling a bitstream from the incoming packets and thensubsequently repacketizing the reassembled bitstream into a differentset of packets facilitates uniform processing and/or transmission ofaudio content by the sourcing playback device and by other playbackdevices that receive the audio content from the sourcing playbackdevice. However, for some delay-sensitive audio content, reassembly andrepacketization may be undesirable, and therefore, in some embodiments,the sourcing playback device may not perform reassembly andrepacketization for some (or all) audio content that it receives beforeplaying the audio content and/or transmitting the audio content to otherplayback devices.

In some embodiments an audio source provides audio content in digitalform to a sourcing playback device, e.g., via a digital line-ininterface. In such embodiments, the sourcing playback device packetizesthe digital audio into packets of audio content before transmitting theaudio content to other playback devices. In some embodiments, individualpackets of the audio content comprise a sequence number or otheridentifier so that, when other playback devices receive the audiocontent, those other playback devices will be able to reliably arrangethe received packets in the correct order before performing furtherpacket processing.

In some embodiments an audio source provides audio content in analogform to a sourcing playback device, e.g., via an analog line-ininterface. In such embodiments, the sourcing playback device convertsthe received analog audio into digital audio and packetizes the digitalaudio into packets of audio content before transmitting the audiocontent to other playback devices. In some embodiments, individualpackets of the audio content comprise a sequence number or otheridentifier so that, when other playback devices receive the audiocontent, those other playback devices will be able to reliably arrangethe received packets in the correct order before performing furtherpacket processing.

After obtaining audio content from an audio source or from anotherplayback device, a playback device in some embodiments one or more of(i) plays the audio content individually, (ii) plays the content insynchrony with one or more additional playback devices, and/or (iii)transmits the audio content to one or more other playback devices.

b. Playback Timing

The playback devices disclosed and described herein use playback timingto play audio content in synchrony with each other. An individualplayback device can generate playback timing and/or playback audiocontent according to playback timing, based on the playback device'sconfiguration in the media playback network. The sourcing playbackdevice that generates the playback timing for audio content alsotransmits that generated playback timing to all the playback devicesthat are configured to play the audio content. In some embodiments, thesourcing playback device transmits the playback timing to a multicastnetwork address, and all the other playback devices configured to playthe audio content receive the playback timing via that multicastaddress. In some embodiments, the sourcing playback device alternativelytransmits the playback timing to each unicast network address of eachother playback device configured to play the audio content, and each ofthe other playback devices configured to play the audio content receivethe playback timing via its unicast address.

In operation, a playback device (or a computing device associated withthe playback device) generates the playback timing for audio contentbased on clock timing (described below), which can be “local” clocktiming (i.e., clock timing generated by the sourcing playback device) or“remote” clock timing received from a different playback device (ordifferent computing device).

In some embodiments, the playback timing is generated for individualframes (or packets) of audio content. As described above, in someembodiments, the audio content is packaged in a series of frames (orpackets) where individual frames (or packets) comprise a portion of theaudio content. In some embodiments, the playback timing for the audiocontent includes a playback time for each frame (or packet) of audiocontent. In some embodiments, the playback timing for an individualframe (or packet) is included within the frame (or packet), e.g., in theheader of the frame (or packet), in an extended header of the frame (orpacket), and/or in the payload portion of the frame (or packet).

In some embodiments, the playback time for an individual frame (orpacket) is identified within a timestamp or other indication. In suchembodiments, the timestamp (or other indication) represents a time toplay audio content within that individual frame (or packet). Inoperation, when the playback timing for an individual frame (or packet)is generated, the playback timing for that individual frame (or packet)is a future time relative to a current clock time of a reference clockat the time that the playback timing for that individual frame (orpacket) is generated. The reference clock can be a “local” clock at theplayback device or a “remote” clock at a separate network device, e.g.,another playback device, a computing device, or another network deviceconfigured to provide clock timing for use by playback devices togenerate playback timing and/or playback audio content.

In operation, a playback device tasked with playing particular audiocontent will play the portion(s) of the particular audio content withinan individual frame (or packet) at the playback time specified by theplayback timing for that individual frame (or packet), as adjusted toaccommodate for clocking differences between the sourcing playbackdevice, the clock timing, and the playback device that is tasked withplaying the audio content, as describe in more detail below.

c. Clock Timing

The playback devices disclosed and described herein use clock timing togenerate playback timing for audio content and to play the audio contentbased on the generated playback timing. In some embodiments, thesourcing playback device uses clock timing from a reference clock (e.g.,a device clock, a digital-to-audio converter clock, a playback timereference clock, or any other clock) to generate playback timing foraudio content that the sourcing playback device receives from an audiosource. For an individual playback device, the reference clock can be a“local” clock at the playback device or a “remote” clock at a separatenetwork device, e.g., another playback device, a computing device, oranother network device configured to provide clock timing for use byplayback devices to generate playback timing and/or playback audiocontent.

In some embodiments, all of the playback devices tasked with playingparticular audio content in synchrony use the same clock timing from thereference clock to play back that particular audio content. In someembodiments, playback devices use the same clock timing to play audiocontent that was used to generate the playback timing for the audiocontent.

In operation, the network device that generates the clock timing alsotransmits the clock timing to all the playback devices in the networkthat need to use the clock timing for generating playback timing and/orplaying back audio content. In some embodiments, the network device thatgenerates the clock timing transmits the clock timing to a multicastnetwork address, and all the other playback devices configured togenerate playback timing and/or play audio content receive the clocktiming via that multicast address. In some embodiments, the networkdevice alternatively transmits the clock timing to each unicast networkaddress of each other playback device configured to play the audiocontent, and each of the other playback devices configured to play theaudio content receive the clock timing via its unicast address.

d. Generating Playback Timing with Clock Timing from a Local Clock

In some embodiments, a sourcing playback device (i) generates playbacktiming for audio content based on clock timing from a local clock at thesourcing playback device, and (ii) transmits the generated playbacktiming to all other playback devices configured to play the audiocontent. In operation, when generating playback timing for an individualframe (or packet), the “sourcing” playback device adds a “timingadvance” to the current clock time of the local clock of the sourcingplayback device that the sourcing playback device is using forgenerating the playback timing.

In some embodiments, the “timing advance” is based on an amount of timethat is greater than or equal to the sum of (i) the network transit timerequired for frames and/or packets comprising audio content transmittedfrom the sourcing playback device to arrive at all other playbackdevices that are configured to use the playback timing for playing theaudio content in synchrony and (ii) the amount of time required for allthe other playback devices configured to use that playback timing forsynchronous playback to process received frames/packets from thesourcing playback device for playback.

In some embodiments, the sourcing playback device determines a timingadvance by sending one or more test packets to one or more (or perhapsall) of the other playback devices configured to play the audio contentthat the sourcing device is transmitting, and then receiving testresponse packets back from those one or more of the other playbackdevices. In some embodiments, the sourcing playback device and the oneor more other playback devices negotiate a timing advance via multipletest and response messages. In some embodiments with more than twoadditional playback devices, the sourcing playback device determines atiming advance by exchanging test and response messages with all of theplayback devices, and then setting a timing advance that is sufficientfor the playback device having the longest total of network transmittime and packet processing time.

In some embodiments, the timing advance is less than about 50milliseconds. In some embodiments, the timing advance is less than about20-30 milliseconds. And in still further embodiments, the timing advanceis less than about 10 milliseconds. In some embodiments, the timingadvance remains constant after being determined. In other embodiments,the playback device that generates the playback timing can change thetiming advance in response to a request from a receiving deviceindicating that a greater timing advance is required (e.g., because thereceiving device is not receiving packets comprising portions of audiocontent until after other devices have already played the portions ofaudio content) or a shorter timing advance would be sufficient (e.g.,because the receiving device is buffering more packets comprisingportions of audio content than necessary to provide consistent, reliableplayback).

As described in more detail below, all the playback devices configuredto play the audio content in synchrony will use the playback timing andthe clock timing to play the audio content in synchrony with each other.

e. Playing Audio Content using Local Playback Timing and Local ClockTiming

In some embodiments, the sourcing playback device is configured to playaudio content in synchrony with one or more other playback devices. Andif the sourcing playback device is using clock timing from a local clockat the sourcing playback device to generate the playback timing, thenthe sourcing playback device will play the audio content usinglocally-generated playback timing and the locally-generated clocktiming. In operation, the sourcing playback device plays an individualframe (or packet) comprising portions of the audio content when thelocal clock that the sourcing playback device used to generate theplayback timing reaches the time specified in the playback timing forthat individual frame (or packet).

For example, recall that when generating playback timing for anindividual frame (or packet), the sourcing playback device adds a“timing advance” to the current clock time of the reference clock usedfor generating the playback timing. In this instance, the referenceclock used for generating the playback timing is a local clock at thesourcing playback device. So, if the timing advance for an individualframe is, for example, 30 milliseconds, then the sourcing playbackdevice plays the portion (e.g., a sample or set of samples) of audiocontent in an individual frame (or packet) 30 milliseconds aftercreating the playback timing for that individual frame (or packet).

In this manner, the sourcing playback device plays the audio contentusing locally-generated playback timing and clock timing from a localreference clock. As described further below, by playing the portion(s)of the audio content of an individual frame and/or packet when the clocktime of the local reference clock reaches the playback timing for thatindividual frame or packet, the sourcing playback device plays thatportion(s) of the audio content in that individual frame and/or packetin synchrony with other playback devices.

f. Playing Audio Content Using Remote Playback Timing and Remote ClockTiming

Recall that, in some embodiments, the sourcing playback device transmitsthe audio content and the playback timing for the audio content to oneor more other playback devices. And further recall that, in someembodiments, the network device providing the clock timing can be adifferent device than the sourcing playback device. Playback devicesthat receive the audio content, the playback timing, and the clocktiming from another playback device are configured to playback the audiocontent using the playback timing from the sourcing playback device(i.e., remote playback timing) and clock timing from a clock at anotherplayback device (i.e., remote clock timing). In this manner, thereceiving playback device in this instance plays audio content usingremote playback timing and remote clock timing.

To play an individual frame (or packet) of the audio content insynchrony with every other playback device tasked with playing the audiocontent, the receiving playback device (i) receives the frames (orpackets) comprising the portions of the audio content from the sourcingplayback device, (ii) receives the playback timing for the audio contentfrom the sourcing playback device (e.g., in the frame and/or packetheaders of the frames and/or packets comprising the portions of theaudio content or perhaps separately from the frames and/or packetscomprising the portions of the audio content), (iii) receives the clocktiming from another network device, e.g., another playback device, acomputing device, or another network device configured to provide clocktiming for use by playback devices to generate playback timing and/orplayback audio content, and (iv) plays the portion(s) of the audiocontent in the individual frame (or packet) when the local clock thatthe receiving playback device uses for audio content playback reachesthe playback time specified in the playback timing for that individualframe (or packet) received from the sourcing playback device, asadjusted by a “timing offset.”

In operation, after the receiving playback device receives clock timingfrom the other network device, the receiving device determines a “timingoffset” for the receiving playback device. This “timing offset”comprises (or at least corresponds to) a difference between the“reference” clock at the network device that the network device used togenerate the clock timing and a “local” clock at the receiving playbackdevice that the receiving playback device uses to play the audiocontent. In operation, each playback device that receives the clocktiming from another network device calculates its own “timing offset”based on the difference between its local clock and the clock timing,and thus, the “timing offset” that each playback determines is specificto that particular playback device.

In some embodiments, when playing back the audio content, the receivingplayback device generates new playback timing (specific to the receivingplayback device) for individual frames (or packets) of audio content byadding the previously determined “timing offset” to the playback timingfor each frame (or packet) received from the sourcing playback device.With this approach, the receiving playback device converts the playbacktiming for the audio content received from the sourcing playback deviceinto “local” playback timing for the receiving playback device. Becauseeach receiving playback device calculates its own “timing offset,” eachreceiving playback device's determined “local” playback timing for anindividual frame is specific to that particular playback device.

And when the “local” clock that the receiving playback device is usingfor playing back the audio content reaches the “local” playback time foran individual frame (or packet), the receiving playback device plays theaudio content (or portions thereof) associated with that individualframe (or packet). As described above, in some embodiments, the playbacktiming for a particular frame (or packet) is in the header of the frame(or packet). In other embodiments, the playback timing for individualframes (or packets) is transmitted separately from the frames (orpackets) comprising the audio content.

Because the receiving playback device plays frames (or packets)comprising portions of the audio content according to the playbacktiming as adjusted by the “timing offset” relative to the clock timing,and because the sourcing playback generated the playback timing forthose frames (or packets) relative to the clock timing and plays thesame frames (or packets) comprising portions of the audio contentaccording to the playback timing and its determined “timing offset,” thereceiving playback device and the sourcing playback device play the sameframes (or packets) comprising the same portions of the audio content insynchrony, i.e., at the same time or at substantially the same time.

Additional details regarding audio playback synchronization amongplayback devices and/or zones can be found, for example, in U.S. Pat.No. 8,234,395 entitled, “System and method for synchronizing operationsamong a plurality of independently clocked digital data processingdevices,” which is incorporated herein by reference in its entirety.

V. Example Portable Playback Devices

As noted above, certain playback device implementations may beconfigured for portable use. These portable implementations includewearable playback devices, such as headphones and earbuds, generallydesigned for personal listening by one user at a time, and portabledevices designed for out loud playback. FIG. 7A is a partial cutawayview of the media playback system 100 with the inclusion of one or moreportable playback devices 710 (identified individually as portableplayback devices 710 a, 710 b, and 710 c). The portable playback devices710 are similar to the playback devices 110, but are configured forportable use. While they are shown in the home in FIG. 7A, the portableplayback devices 710 are configured to play back audio content while inthe home and while “on the go.”

As shown in the block diagram of FIG. 7B, a portable playback device 710a includes the same or similar components as the playback device 110 a.However, to facilitate portable use, the playback device 710 a may beimplemented in a certain form factor (e.g., headphones or earbuds) andincludes one or more batteries in power 712 i to provide portable power.

Referring to FIG. 7B, the portable playback device 710 a includes aninput/output 711, which can include an analog I/O 711 a and/or a digitalI/O 711 b similar to the components of the playback device 110. Tofacilitate portable usage, the input/output 711 of the portable playbackdevice 710 a may include an interface (such as a Bluetooth interface) tofacilitate connection to a bridge device (e.g., a mobile device), whichthe portable playback device 710 a may use to stream audio content andotherwise communicate with the bridge device.

The playback device 710 a further includes electronics 712, a userinterface 713 (e.g., one or more buttons, knobs, dials, touch-sensitivesurfaces, displays, touchscreens), and one or more transducers 714(referred to hereinafter as “the transducers 714”). The electronics 712is configured to receive audio from an audio source via the input/output711, one or more of the computing devices 106 a-c via the network 104(FIG. 1B), amplify the received audio, and output the amplified audiofor playback via one or more of the transducers 714.

In some embodiments, the playback device 710 a optionally includes oneor more microphones 715 (e.g., a single microphone, a plurality ofmicrophones, a microphone array) (hereinafter referred to as “themicrophones 715”). In some examples, the microphones 715 may include oneor more voice microphones to facilitate voice input for telephone callsand the like. In certain embodiments, for example, playback device 710 acan operate as an NMD (similar to the NMD 120 of FIG. 1F) configured toreceive voice input from a user using the voice microphones andcorrespondingly perform one or more operations based on the receivedvoice input. In further examples, the microphones 715 may include one ormore acoustic noise cancelling (ANC) microphones which, in operation,capture ambient noise in the environment to facilitate cancelling ofthis ambient noise by the playback device 710 a.

In the illustrated embodiment of FIG. 7B, the electronics 712 includeone or more processors 712 a (referred to hereinafter as “the processors112 a”), memory 712 b, software components 712 c, a network interface712 d, one or more audio processing components 712 g (referred tohereinafter as “the audio components 712 g”), one or more audioamplifiers 712 h (referred to hereinafter as “the amplifiers 712 h”),and power 712 i (e.g., one or more power supplies, power cables, powerreceptacles, batteries, induction coils, Power-over Ethernet (POE)interfaces, and/or other suitable sources of electric power). In someembodiments, the electronics 712 optionally include one or more othercomponents 712 j (e.g., one or more sensors, video displays,touchscreens).

The network interface 712 d is configured to facilitate a transmissionof data between the playback device 710 a and one or more other deviceson a data network such as, for example, the links 103 and/or the network104 (FIG. 1B). The network interface 712 d is configured to transmit andreceive data corresponding to media content (e.g., audio content, videocontent, text, photographs) and other signals (e.g., non-transitorysignals) comprising digital packet data including an Internet Protocol(IP)-based source address and/or an IP-based destination address. Thenetwork interface 712 d can parse the digital packet data such that theelectronics 712 properly receives and processes the data destined forthe playback device 110 a.

In the illustrated embodiment of FIG. 7B, the network interface 712 dincludes one or more wireless interfaces 712 e (referred to hereinafteras “the wireless interface 712 e”). The wireless interface 712 e (e.g.,a suitable interface comprising one or more antennae) can be configuredto wirelessly communicate with one or more other devices (e.g., one ormore of the playback devices 110, NMDs 120, control devices 130, otherportable playback devices 710, as well as other devices disclosedherein, such as bridge devices) that are communicatively coupled to thenetwork 104 (FIG. 1B) in accordance with a suitable wirelesscommunication protocol (e.g., WiFi, Bluetooth, LTE). In someembodiments, the network interface 712 d optionally includes a wiredinterface 712 f (e.g., an interface or receptacle configured to receivea network cable such as an Ethernet, a USB-A, USB-C, and/or Thunderboltcable) configured to communicate over a wired connection with otherdevices in accordance with a suitable wired communication protocol. Insome embodiments, the electronics 712 excludes the network interface 712d altogether and transmits and receives media content and/or other datavia another communication path (e.g., the input/output 711).

The audio components 712 g are configured to process and/or filter datacomprising media content received by the electronics 712 (e.g., via theinput/output 711 and/or the network interface 712 d) to produce outputaudio signals. In some embodiments, the audio processing components 712g comprise, for example, one or more digital-to-analog converters (DAC),audio preprocessing components, audio enhancement components, a digitalsignal processors (DSPs), and/or other suitable audio processingcomponents, modules, circuits, etc. In certain embodiments, one or moreof the audio processing components 712 g can comprise one or moresubcomponents of the processors 712 a. In some embodiments, theelectronics 712 omits the audio processing components 712 g. In someaspects, for example, the processors 712 a execute instructions storedon the memory 712 b to perform audio processing operations to producethe output audio signals.

The amplifiers 712 h are configured to receive and amplify the audiooutput signals produced by the audio processing components 712 g and/orthe processors 712 a. The amplifiers 7712 h can comprise electronicdevices and/or components configured to amplify audio signals to levelssufficient for driving one or more of the transducers 714. In someembodiments, for example, the amplifiers 712 h include one or moreswitching or class-D power amplifiers. In other embodiments, however,the amplifiers include one or more other types of power amplifiers(e.g., linear gain power amplifiers, class-A amplifiers, class-Bamplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers,class-E amplifiers, class-F amplifiers, class-G and/or class Hamplifiers, and/or another suitable type of power amplifier). In certainembodiments, the amplifiers 712 h comprise a suitable combination of twoor more of the foregoing types of power amplifiers. Moreover, in someembodiments, individual ones of the amplifiers 712 h correspond toindividual ones of the transducers 714. In other embodiments, however,the electronics 712 includes a single one of the amplifiers 712 hconfigured to output amplified audio signals to a plurality of thetransducers 714.

The transducers 714 (e.g., one or more speakers and/or speaker drivers)receive the amplified audio signals from the amplifier 712 h and renderor output the amplified audio signals as sound (e.g., audible soundwaves having a frequency between about 20 Hertz (Hz) and 20 kilohertz(kHz)). In some embodiments, the transducers 714 can comprise a singletransducer. In other embodiments, however, the transducers 714 comprisea plurality of audio transducers. In some embodiments, the transducers714 comprise more than one type of transducer. For example, thetransducers 714 can include one or more low frequency transducers (e.g.,subwoofers, woofers), mid-range frequency transducers (e.g., mid-rangetransducers, mid-woofers), and one or more high frequency transducers(e.g., one or more tweeters).

FIG. 7C is a front isometric view of the portable playback device 710 aconfigured in accordance with aspects of the disclosed technology. Asshown in FIG. 7C, the portable playback device 710 a is implemented asheadphones to facilitate more private playback as compared with the outloud playback of the playback device(s) 110. As shown, the portableplayback device 710 a (also referred to as headphones 710 a) includes ahousing 716 a to support a pair of transducers 714 a on or around user'shead over the user's ears.

The headphones 710 a also include a user interface 713 a with atouch-sensitive region to facilitate playback controls such as transportand/or volume controls. The touch-sensitive region of the user interface713 a may support gesture controls. For instance, a swipe forward orbackward across the touch-sensitive region may skip forward orbackwards, respectively. Other gestures include a touch-and-hold, aswell as a touch-and-continued hold, which may correspond to variousswapping and grouping functions, as described in further detail below.In some implementations, the user interface 713 a may include respectivetouch-sensitive regions on the exterior of each earcup.

FIG. 7D is a front isometric view of the portable playback device 710 bconfigured in accordance with aspects of the disclosed technology. Asshown in FIG. 7D, the portable playback device 710 b is implemented asearbuds to facilitate more private playback as compared with the outloud playback of the playback device(s) 110, similar to the headphones710 a. As shown, the portable playback device 710 b (also referred to asearbuds 710 b) includes a housing 716 b to support a pair of transducers714 b within a user's ears. The earbuds 710 b also include a userinterface 713 b with a touch-sensitive region to facilitate playbackcontrols such as transport and/or volume controls. The earbuds 9710 bcan be in the form of wired, wireless, or true wireless earbuds.

FIG. 7E is a front isometric view of the portable playback device 710 c.As compared with the headphones 710 a and the earbuds 710 b, theportable playback device 710 c includes one or more larger transducersto facilitate out loud audio content playback. A speaker grill 716 acovers the transducers. Relative to the playback device(s) 110, theportable playback device 710 c may include less powerful amplifier(s)and/or smaller transducer(s) to balance battery life, sound outputcapability, and form factor (i.e., size, shape, and weight) of theportable playback device 710 c. The portable playback device 710 cincludes a user interface 713 c with a touch-sensitive region tofacilitate playback controls such as transport and/or volume controls.

Some portable playback devices 710 are configured to be placed upon adevice base 718. To illustrate, FIG. 7F is a front isometric view of theportable playback device 710 d, which is configured to be placed upon adevice base 718 a. Like the portable playback device 710 c, as comparedwith the headphones 710 a and the earbuds 710 b, the portable playbackdevice 710 d includes one or more larger transducers to facilitate outloud audio content playback. A speaker grill 716 b covers thetransducers. The portable playback device 710 c includes a userinterface 713 d with a touch-sensitive region to facilitate playbackcontrols such as transport and/or volume controls.

The device base 718 a includes protrusions 719 a and 719 b, which alignwith recesses 717 a and 717 b on the portable playback device 710 c.Such protrusions and recesses may facilitate placing the portableplayback device 710 c on the device base 718 a and may improve stabilityof the playback device while it is positioned on the device base 718 a.

In example implementations, the portable playback device 710 c isrotatable about the device base 718 a to control volume of the portableplayback device 710 c. For instance, the portable playback device 710 cmay rotate with respect to the device base 718 a, which may generate avolume control signal in a sensor of the portable playback device 710 cand/or device base 718 a. In another example, a first portion of thedevice base 718 a is rotatable with respect to a second portion of thedevice base 718 a. Rotation of these two portions generates a volumecontrol signal in a sensor of the device base 718 a that controls volumeof the portable playback device 710 c when the portable playback device710 c is placed upon the device base 718 a.

The device base 718 a includes a device charging system. When theplayback device 710 c is placed on device base 718 a, the playbackdevice 710 c may draw current from the charging system to charge one ormore of its batteries. In some examples, the charging system of thedevice base 718 a includes an inductive charging circuit (e.g., a coilthat induces a current in a corresponding coil in the playback device710 c that wirelessly charges one or more batteries of the playbackdevice 710 c). Alternatively, the charging system of the device base 718a includes conductive terminals by which the playback device 710 c maydraw current from the device base 718.

Within examples, the device base 718 a carries an identifier thatdistinguishes that device base 718 a from at least some other devicebases (e.g., other device bases of the media playback system 100, orperhaps other devices bases more broadly). In some implementations, thedevice base 718 a may passively communicate this identifier to theplayback device 710 c when it is placed upon the device base 718 a. Forinstance, a charging circuit of the device base 718 may include acurrent or voltage signature (i.e., a pattern) that is unique ascompared to other device bases. The playback device 710 c may use thisunique signature to identify the device base 718. Alternatively, acharging circuit may superimpose a signal onto the current deliveredfrom the device base 718 a (e.g., current from the device base 718 a mayinclude a higher frequency signal carrying the identifier of the devicebase 718 a). In further examples, the device base 718 a includes an RFIDtag, QR code, or other identifying component that is read by theplayback device 710 c when the playback device 710 c is placed upon thedevice base 718 a.

In some implementations, the device base(s) 718 of the media playbacksystem 100 are associated with respective zones. Placing a portableplayback device 710 on a device base causes the device base to join theassociated zone. Additional details regarding device bases can be found,for example, in U.S. Pat. No. 9,544,701 entitled, “Base Properties in aMedia Playback System,” which is incorporated herein by reference in itsentirety.

In some implementations, the device base 718 a includes a controlsystem. Example control systems of the device base 718 a include one ormore processors and memory. The processor(s) may be clock-drivencomputing components that process input data according to instructionsstored in the memory. Example operations include communicating via acommunications interface (e.g., a BLUETOOTH® interface) with playbackdevice 710 c (e.g., to cause the playback device 710 c to join anassociated zone via one or more instructions) and causing the chargingsystem to supply current to playback device 710 c, among other examples.

Within example implementations, the playback device 710 may operate inone of a first mode and a second mode. Generally, the playback device710 operates in the first mode while in the physical proximity of themedia playback system 100 (e.g., while in the home and connected to thenetwork 104) to facilitate interoperability with the playback devices110 a-n of the media playback system 100 and operates in the second modewhile “on the go,” but the playback device 710 may also be operable inthe second mode while in the physical proximity of the media playbacksystem 100. The portable playback device 710 may switch between modesmanually (e.g., via user input to a user interface 713) or automatically(e.g., based on proximity to one or more playback devices 110 a-n,connection to the network 104, and/or based on the location of themobile device).

The playback device 710 may operate in the first mode while connected toa wireless local area network (e.g., the network 104). Through theconnection to the wireless local area network, the playback device 710may stream audio content from one or more audio sources, including localand remote (e.g., cloud) network locations. Further, in the first mode,the portable playback device 710 may interface with other devices of themedia playback system 100. For instance, the portable playback device710 may form synchrony groupings or other arrangements with the playbackdevices 110 a-n and/or other portable playback devices 710 in the firstmode. Further, in the first mode, the portable playback device 710 maybe controlled by the control device(s) 130 in the same or similar manneras the playback device(s) 110.

The playback device 710 may operate in a second mode when connected viaBLUETOOTH (802.15) to a mobile device. In some aspects, in the secondmode, the portable device operates similarly to conventional BLUETOOTHspeakers or wearable devices. That is, the playback device 710 may pairwith a mobile device, such as a smartphone or tablet, and the user mayplay back the audio output of the mobile device. Similarly, themicrophones 715 a of the portable playback device 710 may provide audioinput to the mobile device. As noted above, this mode can be utilized“on the go” to facilitate playback away from the media playback system100, for example, outside the range of a home network. Further, thismode can be used in proximity to the media playback system 100, whichmay facilitate more private use of the portable playback device 710 a orprovide convenient access to content on the mobile device for playback.

FIG. 7G illustrates an example pairing arrangement between theheadphones 710 a and a mobile device configured as a control device 130a. As noted above, a mobile device may become a control device 130 viathe installation of control application software, which may furtherprovide bridging features to facilitate the control device 130 aoperating as an interface between the headphones 710 a and the mediaplayback system 100.

The control device 130 a may include communications interface(s),processing capabilities, and/or other features that are not necessarilyimplemented in the portable playback device 710 a. By “pairing” theportable playback device 710 a to the control device 130 a, the portableplayback device 710 is able to utilize some of these features. Thisarrangement may permit the portable playback device 710 a to be smallerand more portable, to draw less power, and/or to be less expensive,among other possible benefits.

For instance, in various implementations, the portable playback device710 a may be implemented with or without a communications interface toconnect to the Internet while “on the go” (e.g., a cellular dataconnection). By pairing the portable playback device 710 a to thecontrol device 130 a via a personal area connection such as Bluetooth®(IEEE 802.15) or a wireless local area network connection (IEEE 802.11),the portable playback device 710 a may stream music via an Internetconnection of the control device 130 a and the pairing connection. Inembodiments that include a wireless local area network interface, theportable playback device 710 a may connect directly to a wireless localarea network (e.g., the network 104 (FIG. 1B)) if available.

Similarly, in various implementations, the portable playback device 710a may be implemented with or without a wireless local area networkinterface. By pairing the portable playback device 710 to the controldevice 130 a via a personal area connection such as Bluetooth® (IEEE802.15), the portable playback device 710 a may stream music via anInternet connection of the control device 130 a and the pairingconnection. In this example, the Internet connection of the bridgedevice 860 may be a wireless local area network having a gateway to theInternet or via a cellular data connection.

In an example implementation, the control device 130 a is bonded ordefaults to a particular playback device (e.g., playback device 110 c),bonded zone of playback device (e.g., playback devices 110 l and 110 m)or group of playback devices e.g., a “Kitchen+Dining Room” Group).Alternatively, if the home graph hierarchy is utilized, the controldevice 130 a may be bonded to or defaults to joining a particular Set,Room, or Area. Then, in this configuration, control of the bondedplayback device(s) 110 via a NMD 120 or a control device 130 alsocontrols the paired portable playback device 710 a.

Alternatively, the control device 130 a may itself form a zone or Set.For instance, in one example, control device 130 a may be configured asa “Anne's Portable” zone or an “Anne's Headphones” Set. Configuring thecontrol device 130 a as a zone or Set facilitates control of the pairedheadphones 710 a with the NMD(s) 120 and/or the control device(s) 130 ofthe media playback system 100.

In an alternative implementation, the portable playback device 710 a mayindependently interface with the media playback system 100 as its ownzone or Set. Such an implementation of the portable playback device 710a may include a cellular data connection to facilitate portablestreaming (i.e., streaming away from the media playback system 100and/or the network 104). In this example, the portable playback device710 a may join the media playback system 100 as a zone or Set whenconnected to the network 104 or otherwise in proximity to the playbackdevice(s) 110.

VI. Example Swap Techniques

As noted above, example techniques described herein relate totransitions (or “swaps”) of a playback session between a portableplayback device 710 and one or more playback device(s) 110. During aplayback session swap, playback of audio content stops at a “source”playback device and starts at a “target” playback device at the same orsubstantially the same offset within the audio content. For instance,the media playback system 100 may swap playback between a “source”portable playback device 710 and the one or more “target” playbackdevice(s) 110. In further examples, the media playback system 100 mayswap playback between one or more “source” playback device(s) 110 and a“target” portable playback device 710.

To illustrate, a user may begin listening to audio content via theheadphones 710 a or earbuds 710 b while “on the go” and then swapplayback of the audio content to one or more playback devices 110 a-n tocontinue listening to the audio content out loud at home. In anotherexample, a user may begin listening to audio content via the headphones710 a or earbuds 710 b at home (perhaps so as not to disturb anotherperson in the home) and then swap to one or more playback devices 110a-n to continue listening to the audio content out loud. In a thirdexample, a user may begin listening to audio content out loud via theportable playback device 710 c and then swap to one or more one or moreplayback devices 110 a-n, as the target playback device(s) may havegreater sound output capabilities (e.g., due to more powerfulamplifier(s) and/or larger transducer(s)), be located in a differentroom, be configured in a synchrony group, or for any other reason.

Similarly, a user may be listening to audio content via one or moreplayback devices 110 a-n and the swap playback of the audio content tothe portable playback device 710. For example, a user may be listeningto television audio in the den 101 d (including playback devices 110 h,110 i, 110 j, and 110 k) and then swap playback to earbuds 710 b formore personal listening. As another example, a user may be listening toan Internet radio station in the kitchen 101 h (including playbackdevice 110 b) and then swap playback to headphones 710 a to continuelistening on the go. As a third example, a user may be listening tomusic in the bedroom 101 c (including playback device 110 g) and swapplayback to portable playback device 710 c to take the music out to theyard.

A playback device that has an on-going playback session may maintain orhave access to playback session data that defines and/or identifies theplayback session. The playback session data may include datarepresenting a source of the audio content (e.g., a URI or URLindicating the location of the audio content), as well as an offsetindicating a position within the audio content to start playback. Theoffset may be defined as a time (e.g., in milliseconds) from thebeginning of the audio track or as a number of samples, among otherexamples. In example implementations, the offset may be set to aplayback position in the audio content of the current playback positionto allow time for the target device to start buffering the audiocontent. Then, the source playback device stops playback of the audiocontent at the offset and the target playback device starts playback ofthe audio content at the offset.

The playback session data may include data representing a source of theaudio content (e.g., a URI or URL indicating the location of the audiocontent), as well as an offset indicating a position within the audiocontent to start playback. The offset may be defined as a time (e.g., inmilliseconds) from the beginning of the audio track or as a number ofsamples, among other examples.

The playback session data may further include data representing playbackstate. Playback state may include a playback state of the session (e.g.,playing, paused, or stopped). If the playback session implements aplayback queue, the playback session data may include the playback queuestate, such as the current playback position within the queue.

The playback queue state may also include a queue version. For example,in a cloud queue embodiment, the cloud queue server and the mediaplayback system 100 may use the queue version to maintain consistency.The queue version may be incremented each time the queue is modified andthen shared between the media playback system 100 and cloud queue serverto indicate the most recent version of the queue.

Further, the playback session data may also include authorization data,such as one or more keys and/or tokens. Such authorization data mayinclude a token associated with the user account. During a playbacksession swap, the media playback system 100 may verify that the token isauthorized on both the source and target playback devices. Theauthorization data may further include a token associated with thestreaming audio service, which may enable the target playback device toaccess the audio content at the source. Yet further, the authorizationdata may include a token associate with the playback session, whichenables the target playback device to access the session. Other exampleauthorization data is contemplated as well

In some implementations, an input to a playback device triggers a swap.This input may be referred to as a “playback session swap input.” Withinexamples, a playback session swap input may be provided to a userinterface on the playback device, such as the user interface 313 on theplayback device 320 (FIG. 7D) or the user interface 713 a of theheadphones 710 (FIG. 7B). Alternatively, the playback session swap inputmay be provided to a user interface on a control device 130, such as theuser interface 430 (FIGS. 4A-4D) when the user interface 430 iscontrolling a particular playback device or device(s) (e.g., a zone orzone group).

The playback device receiving a playback session swap input may bereferred to as the “initiating playback device.” Within examples, theinitiating playback device is either the source or the target for theswap. When a portable playback device 710 has a playback sessionon-going (e.g., the portable playback device is actively playing backaudio content, or has an active, but paused, playback session) andreceives a playback session swap input, the portable playback device 710may assume that the user wants to “push” the playback session to anearby playback device 110. Accordingly, the portable playback device710 is identified as the source of the swap and the nearby playbackdevice 110 is identified as the target.

To illustrate, FIG. 8A is a schematic diagram illustrating an examplepush swap between the headphones 710 a (FIG. 7C) and the playback device110 b in the Kitchen 110 h zone (FIG. 7A). As shown in FIG. 8A,initially, the headphones 710 a have a playback session on-going. Then,the user provides a playback session swap gesture to the headphones 710a. The playback session on the headphones 710 a is pushed to theplayback device 110 b. After the push, the Kitchen 110 h zone receivesinformation about the playback session and continues playback of theplayback session, which is on-going on the playback device 110 b.

Conversely, if the portable playback device 710 does not have a playbacksession on-going and receives a playback session swap input, theportable playback device 710 will assume that the user wants to “pull” aplayback session from a nearby playback device 110. Here, the portableplayback device 710 is identified as the target of the swap and thenearby playback device 110 is identified as the source. To illustrate,FIG. 8B is a schematic diagram illustrating an example pull swap betweenthe headphones 710 a (FIG. 7C) and the playback device 110 b in theKitchen 110 h zone (FIG. 7A). As shown in FIG. 8B, initially, theplayback device 110 b has a playback session on-going. Then, the userprovides a playback session swap gesture to the headphones 710 a. Theplayback session on the playback device 110 b is pushed to theheadphones 710 a. After the push, the headphones 710 a have the playbacksession.

If both the portable playback device 710 and the nearby playback device110 have on-going playback sessions, it may be unclear whether the userwants to push the playback session on the portable playback device 710to the nearby playback device 110 or pull the playback session on thenearby playback device 110 to the portable playback device 710. In someimplementations the portable playback device 710 may assume that theuser would like to “push” the playback session to a nearby playbackdevice 110. To illustrate, FIG. 8C is a schematic diagram illustratingan example push swap between the headphones 710 a (FIG. 7C) and theplayback device 110 b in the Kitchen 110 h zone (FIG. 7A). As shown inFIG. 8C, initially, both the headphones 710 a and the playback device110 b have a playback session on-going. Then, the user provides aplayback session swap gesture to the headphones 710 a. The playbacksession on the headphones 710 a is pushed to the playback device 110 b.After the push, the Kitchen 110 h zone has the playback session from theheadphones 710 a, which is on-going on the playback device 110 b. If theuser would instead like to “pull” the playback session on the nearbyplayback device 110 instead, the user may stop the playback session onthe portable playback device 710 first, then provide a playback sessionswap input to the portable playback device 710. In alternateimplementations, the portable playback device 710 may be configured tomake the opposite assumption.

In the FIG. 8A-8C examples, the initiating device is the headphones 710a. In other examples, the user may provide a playback session swap inputto one of the playback devices 110, such as the playback device 110 b.In this scenario, similar assumptions may apply in designating thesource and target of the swap. In particular, when the playback device110 b has a playback session on-going and receives a playback sessionswap input, the playback device 110 b may assume that the user wants to“push” the playback session to a nearby portable playback device 710.Conversely, if the playback device 110 b does not have a playbacksession on-going and receives a playback session swap input, theplayback device 110 b will assume that the user wants to “pull” aplayback session from a nearby portable playback device 710.

Within examples, the initiating playback device of a swap may identifythe other playback devices in the swap based on proximity to theinitiating playback device. That is, the initiating playback device mayidentify one or more nearby playback devices as targets for a push swapfrom the initiating playback device or as a source for a pull swap tothe initiating playback device. After or based on receiving a playbacksession swap input, the initiating playback device may identify suchnearby playback devices automatically (i.e., without necessarilyreceiving further user input from the playback session swap input).

Some example techniques for identifying nearby playback devices involveaudio-based identification. In exemplary audio-based identificationtechniques, the initiating playback device requests that swap-eligibleplayback devices emit an identifiable sound (such as an audio chirp),which can be detected by one or more microphones of the initiatingplayback device. The initiating playback device may then identify nearbyplayback devices based on the characteristics of the detected sounds.

To illustrate, FIG. 9 is a schematic diagram illustrating an audio-basedidentification technique using an audio chirp. An audio chirp includesacoustic characteristics (e.g., one or more tones) that enableidentification of the playback device transmitting the audio chirp. InFIG. 9 , a user has initiated a swap on a portable playback device 710(here, the headphones 710 a). As noted above, if a playback session ison-going on the headphones 710 a, the headphones 710 a will assume thatthe user desires to push the playback session to one or more nearbyplayback devices. Otherwise, the headphones 710 a will assume that theuser desires to pull a playback session on one or more nearby playbackdevices to the headphones 710 a.

After or based on receiving a playback session swap input, theheadphones 710 a may identify swap-eligible playback devices in themedia playback system 100. For a push swap, the set of swap-eligibleplayback devices may include playback devices of a certain type or thatare assigned a certain role in the media playback system 100. Forinstance, other portable playback devices may be configured asineligible for swap. As another example, only the master in a bondedzone (e.g., a stereo pair or surround sound configuration) may beconsidered swap-eligible. For a pull swap, the set of swap-eligibleplayback devices include playback devices that have on-going playbacksessions. This set may be further narrowed based on other factors, suchas those noted above.

As noted above in section II, the playback devices 110 in the mediaplayback system 100 may maintain or have access to state variablesrepresenting the state of the playback devices and other configurationinformation. This state information is updated periodically or on anevent-based basis (e.g., when state changes), such as via subscriptionsto certain types of events or statuses (e.g., playback event, groupingevent, topology change event, player volume event, group volume event,playback metadata event) and notifications of specific events. Theprotocol used for the subscriptions may be uPnP based or a proprietarycontroller protocol or API. Portable playback devices 710, including theheadphones 710 a and earbuds 719 b, may similarly maintain or haveaccess to these state variables and determine the set of swap-eligibleplayback devices based on the information in the state variables. Thestate variables may be received from another playback device in themedia playback system and/or received from state information stored in aremote computing system in the cloud. In the FIG. 9 example, theheadphones 710 a have identified the playback device 110 b, the playbackdevice 110 g, and the playback device 100 g as swap-eligible playbackdevices.

After identifying the swap-eligible playback devices, the headphones 710a, as the initiating playback device in the swap, causes theswap-eligible playback devices to emit respective audio chirps. Forexample, the headphones 710 a may send instructions to the playbackdevice 110 b, the playback device 110 g, and the playback device 100 gto cause these swap-eligible playback devices to emit unique audiochirps. In some examples, the audio chirps may be ultrasonic (e.g.,greater than 20 kHz) or near-ultrasonic (e.g., 19-20 kHz), to avoidpropagation of the audio chirp outside the proximity of the emittingplayback device and/or to avoid user distraction.

Each audio chirp may include data in the form of an encoded identifier.Each encoded identifier may be different and encoded as a set of tones,which is known to the initiating playback device. The audio chirps canbe transmitted by the swap-eligible playback devices simultaneously,concurrently, or sequentially or when the particular playback devicereceives the instruction to transmit the audio chirp. In some examples,a device in the media playback system may provide timing information asto when to transmit the audio chirp for each of the playback devices.

After instructing the swap-eligible playback devices to emit the audiochirps, the initiating playback device in the swap attempts to detectthe emitted audio chirps via one or more microphones (e.g., themicrophones 715). For instance, the headphones 710 a may attempt todetect the emitted audio chirps via one or more voice microphones in thehousing of the headphones 710 a. Alternatively, the headphones 710 a mayattempt to detect the emitted audio chirps via one or more ANCmicrophones in the housing of the headphones 710 a. In some instances,particular microphones (ANC or voice) may be selected or tuned to besensitive to the ultrasonic or near-ultrasonic range such that thesemicrophones are particularly suited to receiving the audio chirp. Otherexamples are possible as well.

To identify the “nearby” playback device, the initiating playback devicemay compare the detected audio chirps. For instance, the headphones 710a may compare various metrics such as sound pressure and signal-to-noiseratio of the detected audio chirps to identify the “loudest” audiochirp, which may be assumed to have been emitted by the playback devicethat is physically nearest to the initiating playback device. In exampleimplementations, the initiating playback device may list or otherwiserank the swap-eligible playback devices by relative signal strength(e.g., SNR) and then select the highest ranked swap-eligible playbackdevice as the source or target for the swap.

As shown in FIG. 9 , the headphones 710 a detect audio chirps emitted bythe playback devices 110 n and the playback device 110 g, which are inthe Bathroom 101 a and the Bedroom 101 c, respectively. However, theheadphones 710 a did not detect the audio chirp emitted by the playbackdevice 110 b, perhaps because the audio chirp could not propagate to theheadphones 710 a from the Kitchen 101 h, which is on a different floorof the house relative to the other zones. In this example, the playbackdevice 110 n is determined to be the nearest playback device, as acomparison of the metrics of the audio chirp emitted by the playbackdevice 110 n and the audio chirp emitted by the playback device 110 gindicated that the audio chirp emitted by the playback device 110 n was“loudest.”

To facilitate comparison between the detect audio chirps, theswap-eligible playback devices may emit the audio chirps at the same orsubstantially the same volume level. In some cases, the instructions toemit the audio chirps include instructions to change to a certain volumelevel. Since different playback devices have different types oftransducers and/or amplifiers, the volume level for each playback deviceemitting the chirp may vary based on the type of device. Alternatively,the playback devices may be pre-configured to emit audio chirps at thecertain volume level.

The playback session swap input may take various forms. For instance, aparticular input to user interface 713 a of the headphones 710 (FIG. 7B)such as a tap or gesture to the touch-sensitive region (or a portionthereof) may trigger the swap. In further examples, the portableplayback device 710 may include a physical button to trigger the swap.Yet further, a pattern of touch-inputs (e.g. short, long, short) or atracing pattern (e.g., a shape such as a zig-zag or triangle) maytrigger a swap. Other types of inputs are contemplated as well.

In some particular examples, a touch-and-hold or a continuedtouch-and-hold to a particular area on the touch-sensitive region (e.g.,a play/pause area) triggers a swap. To illustrate, FIG. 10 is a chartillustrating an exemplary control scheme for the portable playbackdevice 710 c, the playback device(s) 110, and the headphones 710 a. Asshown in FIG. 10 , a user may provide a press input (a.k.a. touch) to atouch-sensitive region to perform a primary action (i.e., play orpause). If a physical button is available for swap, the user can pushand hold the physical button to invoke a swap.

If the user continues to hold the press input (touch-and-hold), asecondary action is performed. For the portable playback device 710 cand the playback device(s) 110, the secondary action is to group withnearby playback device(s). That is, the initiating playback device(i.e., the portable playback device 710 c or the playback device(s) 110)forms a synchrony group with nearby playback devices. In contrast, forthe headphones 710 a, the secondary action is to perform a push swap ora pull swap, as described in connection with FIGS. 8A-8C. Thisconfiguration allows a user to more quickly access the swap functionwhen using the headphones 710 a. Since wearable playback devices aredesigned for relatively private listening compared with the portableplayback device 710 c and the playback device(s) 110, the user is lesslikely to desire to group the headphones for synchronous playback withthese types of devices. Other example implementations may vary thiscontrol scheme.

If the user continues to further hold the press input(touch-and-continued hold), a tertiary action is performed. For theportable playback device 710 c and the playback device(s) 110, thetertiary action is to perform a push swap or a pull swap with nearbyplayback device(s). For the headphones 710 a, no tertiary action isconfigured. Other example control schemes may configure a tertiaryaction for the headphones 710 a. In some examples, continuing to holdthe touch after the last action in the chain may cancel the input.

For a user, this control scheme provides audible feedback for the swapaction. When a user provides a playback session swap input to a firstplayback device, the user will be confident that the first playbackdevice will either be source or target of the swap (depending on whetherthe first playback device has an on-going playback session) as they haveprovided the triggering input to the first playback device. However, theuser may be less confident that the initiating playback device hascorrectly identified the user's desired target (for a push swap) orsource (for a pull swap). In particular, when using the exampleaudio-based identification techniques described above, the initiatingplayback device has the potential to identify a different playbackdevice as the source or target than the user intended, perhaps due tounique acoustic characteristics of the environment causing an audiochirp emitted from a further away playback device to appear to benearest.

By using this control scheme, when providing a press-and-hold input tothe portable playback device 710 c or the playback device(s) 110, agrouping between the sources and targets of the potential swap (if theuser continues to hold) occurs, causing synchronous out-loud playback onthe sources and targets of the potential swap. In particular, when theinitiating playback device has an on-going playback session, apush-group is performed, which causes the initiating playback device andthe nearby playback devices to play back the on-going playback sessionin synchrony. Conversely, when the initiating playback device does nothave an on-going playback session, a pull-group is performed, whichcauses the initiating playback device and the nearby playback devices toplay back an on-going playback session of the nearby playback devices insynchrony. This out-loud synchronous playback provides a preview to theuser on the sources and targets of the swap that will occur if the usercontinues to hold the input. If the “previewed” playback devices in thegroup are different from the user's desired swap source or target, theuser can provide input to cancel the group and/or swap actions.

Further, in some implementations, the control scheme may facilitate auser selecting the desired source or target of a swap by providingadditional input. In particular, in some examples, the user may cyclethrough swap eligible playback devices by providing one or moreadditional press-and-hold inputs within a threshold period of providingthe preceding input. As noted above, the initiating playback device maylist the swap eligible playback devices by signal strength. In anexample, a second press-and-hold input following the initialpress-and-hold input will select the second swap eligible playbackdevices in the list. Similarly, a third press-and-hold input followingthe initial press-and-hold input will select the third swap eligibleplayback devices in the list. Subsequent inputs will continue to cycledown the list (if further swap eligible playback devices are listed).

In some examples, the portable playback device 710 c may similarlytraverse a list of group eligible playback devices via consecutivetouch-and-hold inputs. The group eligible playback devices may be thesame as the swap eligible playback devices, and identified using thesame or similar audio-based identification techniques. For example, topush/pull group with the nearest playback device 110, a user may providea first touch-and-hold input to the playback device 710 c. To push/pullgroup with the next nearest playback device 110, a user may provide asecond touch-and-hold input to the playback device 710 c within athreshold period of time from the first input. Subsequent touch-and-holdinputs may further traverse the ranked list of swap and/or groupeligible playback devices in the ranked order of nearest to furthest.After the threshold period of time, the user would need to start theinput sequence again to perform the grouping.

If a push-swap gesture is performed on the portable playback device 710c while the portable playback device 710 c is already grouped with thenearest playback device 110, instead of performing a push-swap, theportable playback device 710 c may be configured to push-ungroupinstead.

To aid a user in understanding the control scheme, the source and/ortarget playback device(s) may provide feedback, including audio and/orvisual feedback. To illustrate, FIG. 11 FIG. 10 is a chart showing anexemplary feedback scheme for the portable playback device 710 c and theplayback device(s) 110. As shown in FIG. 11 , at each stage in thecontrol scheme, in conjunction with the respective action, theinitiating playback device (the portable playback device 710 c), whichis the source in this example, provides audio and/or visual feedback.Further, when performing the group and swap actions, the target playbackdevice also provides audio and/or visual feedback. For instance, whengrouping the portable playback device 710 c and the playback device(s)110, each playback device provides respective tonal feedback (denoted inFIG. 11 as two different tones “Marco” and “Polo”) and the sourceplayback device provides visual feedback. When swapping the portableplayback device 710 c and the playback device(s) 110, each playbackdevice provides tonal and visual feedback or only the portable playbackdevice 710 c provides tonal and visual feedback.

After identifying the source or target playback devices of a pull orpush swap, respectively, the initiating playback device causes theplayback session to transition from the source playback device(s) to thetarget playback devices. In example implementations, a swap involvesforming a synchrony group including the source playback device(s) andthe target playback devices. Exemplary synchrony grouping is describedin greater detail in sections III and IV above. In forming the synchronygroup, the target playback device(s) begin to play back audio content insynchrony with the source playback device(s). The source playbackdevice(s) may then be removed from the synchrony group, which completesthe swap. The source playback device may be removed or ungrouped fromthe synchrony group by sending a command to the target device to ungroupfrom the source playback device.

In another example implementation, in a pull swap, the target device maysend a request to the source playback device for playback sessioninformation. The playback session information includes playback stateinformation such as current playlist, track, and offset. In yet anotherexample implementation, in a push swap, the initiating device may send acommand to start playback and include the playback state information.The target playback device may use the playback state information tocontinue playing back the playback session without grouping andungrouping with the source playback device.

Referring back to the example of FIG. 8A, to push the playback sessionfrom the headphones 710 a to the playback device 110 b, the headphones710 a form a synchrony group including the headphones 710 a and theplayback device 110 b, which causes the headphones 710 a and theplayback device 110 b to synchronously play back the playback session.To finish the push swap, the headphones 710 a leave the synchrony group.

In the FIG. 8A example, since the playback session begins on theheadphones 710 a, the headphones 710 a may initially operate as sourcingdevice of the synchrony group. As noted above, the sourcing device, orgroup coordinator, obtains the audio for the synchrony group. After theheadphones 710 a leave the synchrony group, the playback device 110 bmay assume the role of sourcing device.

In some examples, during the swap, to avoid the user being disrupted byaudio playback during the swap, playback may be manipulated by thesource or target playback device. For instance, the playback session maybe paused concurrently with creation of the synchrony group and thenresumed after the headphones 710 a leave the synchrony group. In otherexamples, either the headphones 710 a or the playback device 110 b, orboth, may be muted until the swap is completed. In yet another example,the headphones 710 a may continue playback for x seconds (e.g., 1, 2, 3seconds or the like) before pausing to allow for any delays intransitioning the playback session to the target playback device. Otherexamples are possible as well.

Referring back to the example of FIG. 8B, to pull the playback sessionfrom the playback device 110 b to the headphones 710 a, the headphones710 a form a synchrony group including the headphones 710 a and theplayback device 110 b, which causes the headphones 710 a and theplayback device 110 b to synchronously play back the playback session.To finish the push swap, the playback device 110 b leaves the synchronygroup.

In the FIG. 8B example, since the playback session begins on theplayback device 110 b, the playback device 110 b may initially operateas sourcing device of the synchrony group. As noted above, the sourcingdevice, or group coordinator, obtains the audio for the synchrony group.After the playback device 110 b leave the synchrony group, theheadphones 710 a may assume the role of sourcing device.

In alternate embodiments, instead of leaving the synchrony group tocomplete the swap, the source playback device remains in the synchronygroup as the sourcing device. While this would normally cause the sourceplayback device and the target playback devices to play content insynchrony, in these examples, the source playback device is placed intoa mute state. Since the source playback device is muted, the playbacksession appears to have been swapped from the perspective of the user.This may be a true mute that disables or places certain components, suchas the audio amplifiers, in a low-power state, which reduces powerconsumption relative to out loud playback when not in the mute state.

VII. Example Home Theater Swap Techniques

In some examples, a user may desire to transition a playback sessionfrom a soundbar-type playback device to a wearable playback device, toenable more private listening of audio from a television or other hometheater source. Example soundbar-type playback devices include theplayback device 110 h (FIGS. 1K and 1J). A soundbar-type playback deviceis capable of receiving audio via an audio input interface from atelevision, media player (e.g., set-top box, streaming media playbackdevice, computer), or other home theater source. Further, asoundbar-type playback device may operate as a sourcing device for abonded zone that includes one or more satellites, which may play backcertain channels (e.g., the playback devices 110 j and 110 k) and/orcertain frequency ranges (e.g., the playback device 110 i), as shown inFIGS. 1K and 1J illustrating the Den 101 d. While some sound-barplayback devices implement a bar-shaped housing to enable multiple audiodrivers to be carried linearly along a front surface, a soundbar-typeplayback device need not necessarily have a bar-shaped housing.

An exemplary sound-bar playback device may be considered to operate inone of two modes for receiving audio content, referred to herein as ahome theater mode and a music mode. In the home theater mode, thesoundbar-type playback device receives audio from a physically-connectedsource (e.g., a television) via the audio input interface. Whenstreaming audio via a network interface, the soundbar-type playbackdevice may be considered to be in the music mode. Notably, the streamedaudio is not necessarily music, but may be other types of streamed audiocontent, such as podcasts or news programs. When streaming audio contentin the music mode, the soundbar-type playback device may perform a swapin the same or similar manner as described in section VI.

While in the home theater mode, to perform a swap, the soundbar-typeplayback device may enter another mode, referred to herein as a “hometheater swap mode,” or simply “swap mode.” When performing a swap actionwith a wearable playback device using the swap mode, the wearableplayback device effectively becomes a satellite of the soundbar-typeplayback device. In the swap mode, the soundbar-type playback devicefunctions as the source device if playing back audio from the audioinput interface in the home theater mode. The wearable playback devicethen functions as the target playback device to receive and play backthe audio from the audio input interface. Conversely, if the wearableplayback device is already playing back the audio from the audio inputinterface in the swap mode, the soundbar-type playback device functionsas the target playback device.

In some cases, the wearable playback device initiates the swap mode.FIG. 12A is an example message flow diagram showing instructionsexchanged between the headphones 710 a, a soundbar-type playback device110 h, one or more satellites in a bonded zone (the Den 101 d) with thesoundbar-type playback device 110 h (illustrated as the playback devices110 j, 110 k, and 110 i, as shown in FIG. 1K), and one or more groupmembers (if the bonded zone is in a zone group with any additionalzones) in an example swap mode initiated by the headphones 710 a.

Before entering the swap mode, at 1281 a, the soundbar-type playbackdevice 110 h is playing back audio from an audio input interface in ahome theater mode. As the sourcing device of the bonded zone thatincludes the satellites, in the home theater mode, the soundbar-typeplayback device 110 h distributes audio to the satellites according totheir roles in the bonded zone. Further, if the Den 101 d is in a zonegroup with one or more other zones, the soundbar-type playback device110 h distributes full-range audio content to the group members of thezone group as the sourcing device of the zone group.

At 1282 b, the headphones 710 a receive a playback session swap input,which may be a touch-and-hold input, among other examples as describedin connection with section VI. In this example, the headphones thenidentify the soundbar-type playback device 110 h as the source for theswap (e.g., based on determining that the soundbar-type playback device110 h is the physically nearest playback device using an audio-basedidentification technique).

Then, at 1283 a, the headphones 710 a send data to the soundbar-typeplayback device 110 h representing instructions to transition to theswap mode, which are received by the soundbar-type playback device 110h. The headphones 710 a and the soundbar-type playback device 110 h maysend and receive the data representing the instructions via respective802.11-compatible network interfaces. The headphones 710 a may send thisdata based on receiving the playback session swap input.

Based on receiving the data representing the instructions to enter theswap mode, the soundbar-type playback device 110 h transitions from thehome theater mode to the swap mode. More particularly, at 1284 a, thesoundbar-type playback device 110 h adds the headphones 710 a to abonded zone, which may be the same bonded zone as the Den 101 d or a newbonded zone.

In some examples, in the home theater mode, the soundbar-type playbackdevice 110 h and the satellites operate as nodes in a mesh network. Asdescribed above in connection with FIG. 1B, in some implementations, thenetwork(s) 104 may include a dedicated communication network implementedas a mesh network. In the home theater mode, the soundbar-type playbackdevice 110 h distributes playback timing information and audio to thesatellites using the mesh network.

To facilitate adding headphones 710 a to the bonded zone, thesoundbar-type playback device 110 h transitions its 802.11-compatiblenetwork interface from operating as a node in a mesh network tooperating as an access point. The access point forms a first wirelesslocal area network (LAN) in a first wireless frequency band (e.g., the 5Ghz band). The soundbar-type playback device 110 h then sends, via the802.11-compatible network interface to the first wearable playbackdevice, data representing a service set identifier (SSID) of the firstwireless LAN and credentials for the first wireless LAN, which allowsthe headphones 710 a to connect to the first wireless LAN. After thefirst wearable playback device connects to the first wireless LAN formedby the soundbar-type playback device, the soundbar-type playback device110 h forms a bonded zone that includes the soundbar-type playbackdevice 110 h and the headphones 710 a. This may be considered to be thesame bonded zone as the Den 101 d or a new bonded zone. At 1285 a, afterconnecting to the first wireless LAN, the headphones 710 a send amessage to the soundbar-type playback device 110 h to start streamingthe HT audio stream.

Further, in some examples, while in the swap mode, the headphones 710 beffectively becomes a satellite of the soundbar-type playback device 110h. As such, the soundbar-type playback device 110 h “parks” thesatellite playback devices 110 j, 110 k, and 110 i on a second wirelessLAN in a second wireless frequency band (e.g., the 2.4 Ghz band) becausethe satellite playback devices 110 j, 110 k, and 110 i will not beplaying back audio. Parking the satellites on the second LAN allows thesatellites to remain contactable (e.g., to eventually re-form the bondedzone when transitioning back to the home theater mode) and to receiveupdates on the state of the media playback system 100 (e.g., statevariable events). The soundbar-type playback device 110 h may form thissecond wireless LAN using its 802.11-compatible network interface.

At 1286 a, the soundbar-type playback device 110 h stops streaming theHT audio stream to the satellites (e.g., 110 j, 110 k, and 110 i). Thismay be performed as part of or in connection with parking the satelliteplayback devices 110 j, 110 k, and 110 i on a second wireless LAN.Similarly, at 1287 a, the soundbar-type playback device 110 h may stopstreaming the HT audio stream to the group members, if any. Forming anew bonded zone at 1284 a may remove the soundbar-type playback device110 h from any existing zone group, which causes the group members tostop receiving the HT audio stream.

At 1288 a, the soundbar-type playback device 110 h streams the HT audiostream to the headphones 710 a for playback. In connection with theheadphones 710 a receiving the stream and playing back the audio, thesoundbar-type playback device 110 h mutes to complete the swap. Whenmuted, the soundbar-type playback device 110 h may continue to processaudio data for playback synchronously with the headphones 710 a. The HTaudio stream may include data representing playback timing informationfor the bonded zone and the audio. In some examples, the audio ismulti-channel audio such as a surround sound track. In such examples,the soundbar-type playback device 110 h may down-mix the surround soundaudio track to an audio track with fewer channels, such as stereo audiotrack. The surround sound audio track can be down-mixed to contain thesame number of channels supported by the wearable device or the portableplayback device.

While in the swap mode, the soundbar-type playback device 110 h maydetect an event representing a trigger to transition from operating inthe swap mode to operating in the home theater mode. Such an event mayinclude receiving, from the headphones 710 a, data representinginstructions to transition to the home theater mode (e.g., to end theswap mode), which the headphones 710 a may send after receiving aplayback session swap input while in the swap mode. As another example,the soundbar-type playback device 110 h may detect that the headphones710 a have disconnected from the first wireless LAN (and are such nolonger operating as a satellite) or been paused for x amount of time.Based on detecting such as event, the soundbar-type playback device 110h may transition to the home theater mode.

Transition to the home theater mode from the swap mode may involve thesoundbar-type playback device 110 h transitioning its 802.11-compatiblenetwork interface from operating as the access point to operating as thenode in the mesh network. Further, the soundbar-type playback device 110h may cause the satellite playback devices to connect to the meshnetwork. Yet further, the soundbar-type playback device 110 h mayre-form the bonded zone that includes the soundbar-type playback device110 h and the satellite playback devices 110 j, 110 k, and 110 i.

Yet further, while in the swap mode, additional wearable playbackdevices may connect to the soundbar-type playback device 110 h assatellites. This may allow, for example, two partners to listen totelevision audio using individual wearable devices in the Den 101 hwithout waking up sleeping children in the adjacent Bedroom 101 c. Auser may cause a second wearable playback device (e.g., the earbuds 710b) to join the swap mode by providing a playback session swap input(e.g., a touch-and-hold) to the second wearable device, which causes thesecond wearable playback device to send data representing instructionsto transition to the swap mode to the soundbar-type playback device 110h. The soundbar-type playback device 110 h then joins the secondwearable device using the techniques shown in FIG. 12A.

In some cases, a control device initiates the swap mode. FIG. 12B is anexample message flow diagram showing instructions exchanged between thecontrol device 130 a, the headphones 710 a, a soundbar-type playbackdevice 110 h, and one or more satellites in a bonded zone (the Den 101d) with the soundbar-type playback device 110 h in an example swap modeinitiated by the control device 130 a.

Before entering the swap mode, at 1281 b, the soundbar-type playbackdevice 110 h is playing back audio from an audio input interface in ahome theater mode. As the sourcing device of the bonded zone thatincludes the satellites, in the home theater mode, the soundbar-typeplayback device 110 h is a master device that distributes audio to thesatellites according to their roles in the bonded zone. Further, if theDen 101 d is in a zone group with one or more other zones, thesoundbar-type playback device 110 h distributes full-range audio contentto the group members of the zone group as the sourcing device of thezone group.

At 1282 b, the control device 130 a, receive a playback session swapinput. The control device 130 may receive a playback session swap inputvia a user interface, such as the user interface 430. More particularly,a particular user interface 430 may control the headphones 430 a, andmay include one or more controls that when selected, correspond to theplayback session swap input.

Then, at 1283 b, the control device 130 a sends a swap command to theheadphones, and the headphones send instructions to the soundbar-typeplayback device to transition to the swap mode. Alternatively, thecontrol device 130 a send data to the soundbar-type playback device 110h representing instructions to transition to the swap mode, which arereceived by the soundbar-type playback device 110 h. The control device130 a and the soundbar-type playback device 110 h may send and receivethe data representing the instructions via respective 802.11-compatiblenetwork interfaces. The control device 130 a may send this data based onreceiving the playback session swap input.

Based on receiving the data representing the instructions to enter theswap mode, the soundbar-type playback device 110 h transitions from thehome theater mode to the swap mode. More particularly, at 1284 b, thesoundbar-type playback device 110 h adds the headphones 710 a to abonded zone, which may be the same bonded zone as the Den 101 d (e.g.,identified as “Den” or a new bonded zone (e.g., identified as “Den+Ben'sHeadphones”).

Similar to the FIG. 12A example, in some examples, in the home theatermode, the soundbar-type playback device 110 h and the satellites operateas nodes in a mesh network. To facilitate adding headphones 710 a to thebonded zone, the soundbar-type playback device 110 h transitions its802.11-compatible network interface from operating as a node in a meshnetwork to operating as an access point. The access point forms a firstwireless local area network (LAN) in a first wireless frequency band(e.g., the 5 Ghz band). The soundbar-type playback device 110 h thensends, via the 802.11-compatible network interface to the first wearableplayback device, data representing a service set identifier (SSID) ofthe first wireless LAN and (ii) credentials for the first wireless LAN,which allows the headphones 710 a to connect to the first wireless LAN.

After the first wearable playback device connects to the first wirelessLAN formed by the soundbar-type playback device, the soundbar-typeplayback device 110 h forms a bonded zone that includes thesoundbar-type playback device 110 h and the headphones 710 a. This maybe considered to be the same bonded zone as the Den 101 d or a newbonded zone. At 1285 b, after connecting to the first wireless LAN, theheadphones 710 a send a message to the soundbar-type playback device 110h to start streaming the HT audio stream. At 1286 c, the control devicereceives data indicating that the headphones 710 a are ready to receiveaudio from the soundbar-type playback device 110 h.

Further, in some examples, while in the swap mode, the headphones 710 beffectively become a satellite of the soundbar-type playback device 110h. As such, since the headphones 710 b are using the first wireless LANon the first wireless band, the soundbar-type playback device 110 h“parks” the satellite playback devices 110 j, 110 k, and 110 i on asecond wireless LAN in a second wireless frequency band (e.g., the 2.4Ghz band). Parking the satellites on the second LAN allows thesatellites to remain contactable (e.g., to eventually re-form the bondedzone when transitioning back to the home theater mode) and receiveupdates on the state of the media playback system 100 (e.g., statevariable events). The soundbar-type playback device 110 h may form thissecond wireless LAN using its 802.11-compatible network interface.

At 1287 b, the soundbar-type playback device 110 h stops streaming theHT audio stream to the satellites. This may be performed as part of orin connection with parking the satellite playback devices 110 j, 110 k,and 110 i on a second wireless LAN.

At 1288 b, the soundbar-type playback device 110 h streams the HT audiostream to the headphones 710 a for playback. In connection with theheadphones 710 a receiving the stream and playing back the audio, thesoundbar-type playback device 110 h mutes to complete the swap. The HTaudio stream may include data representing playback timing informationfor the bonded zone and the audio. In some examples, the audio ismulti-channel audio such as a surround sound track. In such examples,the soundbar-type playback device 110 h may down-mix the surround soundaudio track to an audio track with fewer channels, such as stereo audiotrack.

VIII. Example Swap Methods

Methods 1300A, 1300B, 1400, and 1500 shown in FIGS. 13A, 13B, 14, and 15present an example swap techniques, according to example embodimentsdescribed herein. These example technique can be implemented within anoperating environment including, for example, the media playback system100 of FIG. 7A, one or more of the playback device 110 a-n, one or moreof the NMDs 130, one or more of the control devices 130, one or one ormore of the portable playback devices 710, as well as other devicesdescribed herein and/or other suitable devices. Further, operationsillustrated by way of example as being performed by a media playbacksystem can be performed by any suitable device, such as a playbackdevice or a control device of a media playback system. Methods 1300A,1300B, 1400, and 1500 may include one or more operations, functions, oractions as illustrated by one or more of blocks shown in FIGS. 13A, 13B,14, and 15 . Although the blocks are illustrated in sequential order,these blocks may also be performed in parallel, and/or in a differentorder than those described herein. Also, the various blocks may becombined into fewer blocks, divided into additional blocks, and/orremoved based upon the desired implementation.

In addition, for the implementations disclosed herein, the flowchartsshow functionality and operation of one possible implementation ofpresent embodiments. In this regard, each block may represent a module,a segment, or a portion of program code, which includes one or moreinstructions executable by a processor for implementing specific logicalfunctions or steps in the process. The program code may be stored on anytype of computer readable medium, for example, such as a storage deviceincluding a disk or hard drive. The computer readable medium may includenon-transitory computer readable medium, for example, such ascomputer-readable media that stores data for short periods of time likeregister memory, processor cache, and Random Access Memory (RAM). Thecomputer readable medium may also include non-transitory media, such assecondary or persistent long term storage, like read only memory (ROM),optical or magnetic disks, compact-disc read only memory (CD-ROM), forexample. The computer readable media may also be any other volatile ornon-volatile storage systems. The computer readable medium may beconsidered a computer readable storage medium, for example, or atangible storage device. In addition, for the implementations disclosedherein, each block may represent circuitry that is wired to perform thespecific logical functions in the process.

a. Example Method To Pull Swap

Method 1300A illustrates an example pull swap technique. A portableplayback device, such as a the headphones 710 a, the earbuds 710 b, orthe portable playback device 710 c, may perform the pull swap techniqueto pull audio content in a playback session on a playback device 110 tothe portable playback device.

At block 1302A, the method 1300A includes receiving a playback sessionswap input. For instance, the portable playback device 710 may receivedata representing a first playback session swap input. As described inconnection with section VI, when the portable playback device 710 is notpresently playing audio content, a playback session swap input mayinitiate a pull swap between the portable playback device 710 and one ormore source playback device(s). In some examples, the portable playbackdevice 710 receives the playback session swap input via a userinterface. For instance, as discussed in connection with FIG. 10 , theheadphones 710 a may receive a touch-and-hold input. Alternatively, theportable playback device 710 c may receive a continued touch-and-holdinput. In further examples, a control device may receive the playbacksession swap input and instruct a particular wearable or portableplayback device to initiate the playback session swap.

At block 1304A, the method 1300A includes identifying one or more sourceplayback devices within a media playback system. For instance, theportable playback device 710 may identify one or more eligible playbackdevices 110 as source playback devices. Eligible source playback devicesfor a pull swap include playback devices 110 that that are connected toa first wireless LAN (e.g., the network 104 in FIG. 1B) and also playingback audio content in a playback session. As discussed in section VI,the set of eligible source playback devices may be filtered usingvarious other factors, such as playback device type or role.

In some examples, the portable playback device 710 identifies the one ormore source playback devices via an audio-based identificationtechnique, as described in sections VI. In such examples, identifyingthe one or more source playback devices may include identifying a set ofswap-eligible playback devices in the media playback system and thencausing the set of swap-eligible playback devices to emit respectiveaudio chirps that identify the emitting swap-eligible playback devices.The portable playback device 710 may then detect, via one or moremicrophones, the audio chirps emitted by one or more swap-eligibleplayback devices and select the one or more source playback devices fromamong the one or more swap-eligible playback devices based on the audiochirp from the one or more source playback devices indicating that theone or more source playback devices are physically nearest to theportable playback device 710 among the one or more swap-eligibleplayback devices. Selecting the one or more source playback devices mayinclude comparing one or more respective metrics of the detected audiochirps emitted by one or more swap-eligible playback devices todetermine that the one or more source playback devices are physicallynearest to the portable playback device 710 among the one or moreswap-eligible playback devices.

At block 1306A, the method 1300A includes swapping a playback sessionfrom the source playback devices to the portable playback device. Forexample, the portable playback device 710 may transition the playbacksession from the determined one or more source playback devices to theportable playback device 710. Transitioning the playback session mayinclude forming a first synchrony group including the portable playbackdevice 710 and the one or more source playback devices. Forming thefirst synchrony group causes the portable playback device 710 to startplaying the particular audio content of the playback session.

Transitioning the playback session may further include causing playbackof the particular audio content on the one or more source playbackdevices to stop. In some examples, playback of the particular audiocontent on the one or more source playback devices is stopped by the oneor more source playback devices leaving the first synchrony group.Alternatively, playback of the particular audio content on the one ormore source playback devices is stopped by muting the one or more sourceplayback devices. Other examples are possible as well.

b. Example Method To Push Swap

Method 1300B illustrates an example push swap technique. A portableplayback device, such as the headphones 710 a, the earbuds 710 b, or theportable playback device 710 c, may perform the push swap technique topush audio content in a playback session on the portable playback deviceto a nearby playback device 110.

At block 1302B, the method 1300B includes receiving a playback sessionswap input. For instance, the portable playback device 710 may receivedata representing a first playback session swap input. As described inconnection with section VI, when the portable playback device 710 ispresently playing audio content, a playback session swap input mayinitiate a push swap between the portable playback device 710 and one ormore target playback device(s). In some examples, the portable playbackdevice 710 receives the playback session swap input via a userinterface. For instance, as discussed in connection with FIG. 10 , theheadphones 710 a may receive a touch-and-hold input. Alternatively, theportable playback device 710 c may receive a continued touch-and-holdinput. In further examples, a control device may receive the playbacksession swap input and instruct a particular wearable or portableplayback device to initiate the playback session swap.

At block 1304B, the method 1300B includes identifying one or more sourceplayback devices within a media playback system. For instance, theportable playback device 710 may identify one or more eligible playbackdevices 110 as target playback devices. Eligible target playback devicesfor a pull swap include playback devices 110 that that are connected toa first wireless LAN (e.g., the network 104 in FIG. 1B) and also playingback audio content in a playback session. As discussed in section VI,the set of eligible target playback devices may be filtered usingvarious other factors, such as playback device type or role.

In some examples, the portable playback device 710 identifies the one ormore target playback devices via an audio-based identificationtechnique, as described in sections VI. In such examples, identifyingthe one or more target playback devices may include identifying a set ofswap-eligible playback devices in the media playback system and thencausing the set of swap-eligible playback devices to emit respectiveaudio chirps that identify the emitting swap-eligible playback devices.The portable playback device 710 may then detect, via one or moremicrophones, the audio chirps emitted by one or more swap-eligibleplayback devices and select the one or more target playback devices fromamong the one or more swap-eligible playback devices based on the audiochirp from the one or more source playback devices indicating that theone or more target playback devices are physically nearest to theportable playback device 710 among the one or more swap-eligibleplayback devices. Selecting the one or more target playback devices mayinclude comparing one or more respective metrics of the detected audiochirps emitted by one or more swap-eligible playback devices todetermine that the one or more target playback devices are physicallynearest to the portable playback device 710 among the one or moreswap-eligible playback devices. The comparison can be performed by anyof the devices in the media playback system and/or a remote computingsystem.

At block 1306B, the method 1300B includes swapping a playback sessionfrom the portable playback device to the one or more target playbackdevices. For example, the portable playback device 710 may transitionits playback session to the one or more target playback devices.Transitioning the playback session may include forming a first synchronygroup including the portable playback device 710 and the one or moretarget playback devices. Forming the first synchrony group causes theone or more target playback devices to start playing the particularaudio content of the playback session.

Transitioning the playback session may further include causing playbackof the particular audio content on the portable playback device 710 tostop. In some examples, playback of the particular audio content on theone or more source playback devices is stopped by removing the portableplayback device 710 from the first synchrony group. Other examples arepossible as well.

c. Example Home Theater Swap Method

Method 1400 illustrates an example home theater swap technique. Asoundbar-type playback device may perform the home theater swaptechnique to cause a wearable playback device or portable playbackdevice to play back audio received by the soundbar-type playback deviceand transmitted to the swap target device.

At block 1402, the method 1400 includes playing back audio while in ahome theater mode. For instance, a soundbar-type playback device mayplay back audio while in a home theater mode. In some examples, thesoundbar-type playback device is a master device of a first synchronygroup. For instance, an example soundbar-type is the playback device 110h, which may operate as the sourcing device of the Den 101 d bondedzone. This bonded zone includes the playback devices 110 j and 110 kand/or the playback device 110 i, as illustrated in FIGS. 1K and 1J.

At block 1404, the method 1400 includes receiving instructions totransition to a swap mode. For instance, as illustrated in FIG. 12A, theplayback device 110 h may receive data representing instructions totransition to a swap mode from a wearable playback device, such as theheadphones 710 a. As another example, as illustrated in FIG. 12B, theplayback device 110 h may receive data representing instructions totransition to a swap mode from a control device 130.

At block 1406, the method 1400 includes transitioning from the hometheater mode to the swap mode. The soundbar-type playback device maytransition from the home theater mode to the swap mode based onreceiving the data representing the instructions to enter the swap mode.

As described in connection with FIGS. 12A and 12B, transitioning fromthe home theater mode to the swap mode may include various steps. Forinstance, to facilitate the wearable playback device connecting to theplayback device 110 h as a satellite, the playback device 110 h maytransition its 802.11-compatible network interface from operating as anode in a mesh network to operating as an access point that forms afirst wireless local area network (LAN) in a first wireless frequencyband. Further, the playback device 110 h may send, via the802.11-compatible network interface to the wearable playback device,data representing a service set identifier (SSID) of the first wirelessLAN and credentials for the first wireless LAN, which the wearableplayback device may use to connect to the first wireless LAN.

Transitioning from the home theater mode to the swap mode may furtherinclude forming a second synchrony group that includes the soundbar-typeplayback device and the wearable playback device. For instance, theplayback device 110 h and the headphones 710 a may form a second bondedzone after the headphones 710 a connect to the first wireless LAN. Afterforming the second bonded zone, the playback device 110 h may operate asa sourcing device for the second bonded zone. In this role, the playbackdevice 110 h sends, to the headphones 710 a, data representing playbacktiming information for the second synchrony group and the audio. Theheadphones 710 a play back the audio according to the timinginformation, as described in section IV. After forming the secondsynchrony group, the playback device 110 h mutes playback of the audiowhile the headphones 710 a play back the audio.

Transitioning from the home theater mode to the swap mode may furtherinclude parking one or more satellite playback device in a secondwireless LAN. For instance, the playback device 110 h may cause theplayback devices 110 j and 110 k and/or the playback device 110 i toconnect to a second wireless LAN in a second wireless frequency band andleave the first synchrony group.

In further examples, the soundbar-type playback device may add one ormore additional wearable playback devices to the swap mode concurrentlywith a first wearable playback device. For example, while in the swapmode, the playback device 110 h may receive, from a second wearableplayback device such as the earbuds 710 b or another instance of theheadphones 710 a, data representing instructions to transition to theswap mode. Based on receiving the data representing the instructions toenter the swap mode, the playback device 110 h causes the secondwearable playback device to join the second synchrony group.

Causing the second wearable playback device to join the second synchronygroup may include sending, to the second wearable playback device, datarepresenting the SSID of the first wireless LAN and credentials for thefirst wireless LAN. For instance, after the second wearable playbackdevice connects to the first wireless LAN formed by the playback device110 h, the playback device 110 h receives an indication from the secondplayback device that the second playback device is ready for playbackand adds the second wearable playback device to the second synchronygroup that includes the playback device 110 h and the headphones 710 b.Then, the playback device 110 h sends, to the second wearable playbackdevice, data representing the playback timing information for the secondsynchrony group and the audio. The second wearable playback device playsback the audio in synchrony with the first wearable playback devicebased on the playback timing information, as described in connectionwith section VI.

d. Example Swap Method

Method 1500 illustrates another example swap method.

At block 1502, the method 1500 includes detecting a swap trigger. A swaptrigger may initiate a playback session swap between one or more sourceplayback device(s) and one or more target playback device(s). In variousimplementations, a source playback device or a target playback devicedetects the swap trigger and initiates the playback session swap.Alternatively, another associated device, such as the control device 130or the bridge device 860, detects the trigger and initiates the playbacksession swap.

As described herein, some example swap triggers involve detecting useractions, such as user inputs. For instance, a source playback device(e.g., the portable playback device 710) may detect a particular inputrepresenting a swap command and initiate a playback session swap basedon detecting the particular input. As another example, the controldevice 130 may detect a particular input representing a swap command andinitiate a playback session swap based on detecting the particularinput. Other examples are contemplated as well.

Other example swap triggers are based on proximity. For instance, someexample swap triggers involve detecting proximity between a sourceplayback device (or a paired device, such as a control device 130 a) anda target playback device. Further example swap triggers includedetecting proximity of a source playback device (or a paired device,such as a control device 130 a) to a particular location, such as thehome location of the media playback system 100. Other example swaptriggers are described throughout, and other suitable swap triggers arecontemplated as well.

At block 1504, the method 1500 includes determining one or more sourceplayback device(s) and one or more target playback device(s). Asdescribed above, example implementations involve swapping playbackbetween one or more portable playback devices 710 and one or moreplayback devices 110. The portable playback device(s) 710 may operate asthe source playback device(s) or target playback device(s), depending oncontext. The playback device(s) 110 may likewise participate in playbacksession swap as the source playback device(s) or the target playbackdevice(s).

Within examples, a source playback device is determined based oncontext. For instance, if the playback device 710 detects a particularinput representing a swap command, the playback device 710 may initiatea playback session swap as the source playback device based on detectingthis particular input. In another example, if the control device 130detects a particular input representing a command to swap playback fromthe playback device 110, the control device 130 may initiate a playbacksession swap with the playback device 110 as the source playback deviceor may send data indicating the command to the playback device 110 tocause the playback device 110 to initiate a playback session swap as thesource playback device.

In further examples, the context is based on proximity. For instance, ifthe portable playback device 710 detects proximity of one or morepotential target playback devices 110, the portable playback device 710may initiate a playback session swap with the portable playback device710 as the source playback device. As another example, if a pairedcontrol device 130 or bridge device 860 detect proximity of one or morepotential target playback devices 110 and the paired portable playbackdevice 710 is playing back audio content, the paired control device 130or bridge device 860 may initiate a playback session swap with thepaired portable playback device 710 as the source playback device or maysend data indicating the proximate playback device(s) 110 to the pairedportable playback device 710 to cause the paired portable playbackdevice 710 to initiate a playback session swap as the source playbackdevice.

As described above in section V, in some examples, the one or moretarget devices are determined based on a pre-defined swap pair with thesource playback devices. For instance, as illustrated in FIG. 11A, theKitchen 101 h is designated as a pre-defined swap pair with theheadphones 710 a. As described above, swap pairs can be configuredand/or re-configured via the control device 130, or other suitabledevices.

Alternatively, as described above in section V, the one or more targetdevices are determined based on proximity with the source playbackdevices. Proximity between the source playback device(s) and one or moretarget devices may be determined using any suitable proximity detectiontechnique including the proximity detection techniques described abovein section V. Further, as described above, “proximity” may be defined atone or more ranges, such as a location (e.g., home), zone, area, orindividual device.

Yet further, in other examples, the one or more target devices aredetermined based on context. For instance, one or more playback devicesmay detect a particular input indicating a command designating the oneor more playback devices as target playback devices. In furtherexamples, the one or more target playback devices are determined basedon an association between the target playback devices and a device base.For instance, if the device base 718 a is associated with the kitchen101 h, placement of the portable playback device 710 c on the devicebase 718 a may trigger a playback session swap between the portableplayback device 710 c and the playback device 110 b.

When a first playback device 110 is determined as a source or targetbased on context, one or more additional playback devices 110 may bedetermined based on a synchrony grouping between the first playbackdevice 110 and the one or more additional playback devices 110. Forinstance, if the playback device 110 l in the master bedroom 101 b isdetermined as a target device, the playback device 110 m is alsodetermined as a source playback device based on the bonded pairconfiguration of the playback device 110 m and the playback device 110l. In another example, if a Kitchen+Dining Room Zone group is configuredand the playback device 110 d in the Dining Room receives a swap input,the playback device 110 b is determined as a source playback device aswell. This facilitates a session swap from all playback devices 110participating in the playback session.

At block 1506, the method 1500 includes swapping the playback sessionfrom the one or more source playback device(s) to the one or more targetplayback device(s). Within examples, the method 1500 may implement anysuitable technique to swap the playback session, such as the examplemessaging, cloud queue, and grouping techniques described in section V.Other examples are contemplated as well.

IX. Example Bridge Device

In some example implementations, portable playback devices, such as theheadphones 710 a, the earbuds 710 b, or the portable playback device 710c, may interface with the media playback system 100 via a bridge device860. FIG. 16A illustrates an example pairing arrangement between theheadphones 710 a and a bridge device 860 a. In contrast to a generalpurpose smartphone or tablet which includes bridging features whenconfigured as the control device 130, the bridge device 860 a isconfigured with hardware and software to interface a portable playbackdevice 710 a with the media playback system 100. The bridge device 860 amay also include other features to support or enhance the media playbacksystem 100.

Like the control device 130 a, the bridge device 860 a may includecommunications interface(s), processing capabilities, and/or otherfeatures that are not necessarily implemented in the portable playbackdevice 710 a. When “the portable playback device 710 a is “paired” withthe bridge device 860 a, the portable playback device 710 a is able toutilize some of these features. This arrangement may permit the portableplayback device 710 a to be smaller and more portable, to draw lesspower, and/or to be less expensive, among other possible benefits. Forinstance, similar to the control device 130 a, the bridge device 860 amay include additional communications interfaces as compared with theportable playback device 710 a. For instance, the headphones 710 a mayutilize a cellular data connection of the bridge device 860 a to connectto the Internet. As another example, the headphones 710 a may utilize awireless network interface of the bridge device 860 a to connect to theplayback device(s) 110 via network 104 or to connect to the Internet.

In a further example, the portable playback device 710 may be pairedwith both a mobile device (e.g., a smartphone or tablet, possibleimplementing a control device 130 via installation of controllerapplication software) and a bridge device 860. In such animplementation, the portable playback device 710 a may stream audiocontent from the mobile device via a first network interface (e.g., aBluetooth® network interface) and connect to the bridging device 860 viaa second network interface (e.g., a wireless local area networkinterface). In this arrangement, the mobile device provides a connectionto the Internet to facilitate audio streaming and the bridging device860 functions as an interface to the media playback system 100.

In an example implementation, the bridging device 860 a is bonded to aparticular playback device (e.g., playback device 110 c), bonded zone ofplayback device (e.g., playback devices 110 l and 110 m) or group ofplayback devices e.g., a “Kitchen+Dining Room” Group). Alternatively, ifthe home graph hierarchy is utilized, the bridging device 860 a may bebonded to a particular Set, Room, or Area. Then, control of the playbackdevice(s) 110 that are bonded to the bridging device 860 a via a NMD 120or a control device 130 also controls the paired portable playbackdevice 710 a.

Alternatively, the bridge device 860 a may itself form a zone or Set.For instance, in one example, the bridge device 860 a may be configuredas a “Ben's Headphones” zone or “Ben's Headphones” Set. Configuring thebridge device 860 a facilitates control of the paired headphones 710 awith the NMD(s) 120 and/or the control device(s) 130 of the mediaplayback system 100.

FIG. 16B is a block diagram of a bridge device 860 a comprising aninput/output 811. The input/output 811 can include an analog I/O 811 a(e.g., one or more wires, cables, and/or other suitable communicationlinks configured to carry analog signals) and/or a digital I/O 811 b.The bridge device 860 a further includes electronics 812 and a userinterface 813 (e.g., one or more buttons, knobs, dials, touch-sensitivesurfaces, displays, touchscreens). The bridge device 860 a mayoptionally implement a NMD 820 and include one or more microphones 815(e.g., a single microphone, a plurality of microphones, a microphonearray) (hereinafter referred to as “the microphones 815”) to facilitatevoice input.

In the illustrated embodiment of FIG. 16B, the electronics 812 includesone or more processors 812 a (referred to hereinafter as “the processors812 a”), memory 812 b, software components 812 c, a network interface812 d, and power 812 i. In some embodiments, the electronics 112optionally include one or more other components 812 j (e.g., one or moresensors, video displays, touchscreens).

In some examples, the electronics 812 includes one or more audioprocessing components 812 g (referred to hereinafter as “the audiocomponents 812 g”), one or more audio amplifiers 812 h (referred tohereinafter as “the amplifiers 812 h”), and one or more transducers 814to facilitate voice responses from the NMD 820. However, audio playbackis not the intended purpose of the bridging device and so the audioplayback capabilities are generally very limited compared with theplayback devices 110 and the portable playback devices 710.

The processors 812 a can comprise clock-driven computing component(s)configured to process data, and the memory 812 b can comprise acomputer-readable medium (e.g., a tangible, non-transitorycomputer-readable medium, data storage loaded with one or more of thesoftware components 812 c) configured to store instructions forperforming various operations and/or functions. The processors 812 a areconfigured to execute the instructions stored on the memory 112 b toperform one or more of the operations. The operations can include, forexample, pairing with a particular portable playback device 710 andrelated functions.

The network interface 812 d is configured to facilitate a transmissionof data between the bridging device 860 a and one or more other deviceson a data network such as, for example, the links 103 and/or the network104 (FIG. 1B). In the illustrated embodiment of FIG. 16B, the networkinterface 812 d includes one or more wireless interfaces 812 e (referredto hereinafter as “the wireless interface 812 e”). The wirelessinterface 812 e (e.g., a suitable interface comprising one or moreantennae) can be configured to wirelessly communicate with one or moreother devices (e.g., one or more of the playback devices 110, NMDs 120,control devices 130, and/or portable playback devices 710) that arecommunicatively coupled to the network 104 (FIG. 1B) in accordance witha suitable wireless communication protocol (e.g., WiFi, Bluetooth, LTE).In some examples, the wireless interface 812 e forms an ad-hoc networkwith a paired portable playback device 710. In some embodiments, thenetwork interface 812 d optionally includes a wired interface 812 f(e.g., an interface or receptacle configured to receive a network cablesuch as an Ethernet, a USB-A, USB-C, and/or Thunderbolt cable)configured to communicate over a wired connection with other devices inaccordance with a suitable wired communication protocol.

FIG. 16C is a front isometric view of the bridge device 860 a configuredin accordance with aspects of the disclosed technology as a commanddevice 862 a of the media playback system 100. To configure the bridgedevice 860 a as the command device 862 a, the user interface 813 a ofthe bridge device 860 a includes playback controls. Example playbackcontrols include transport (e.g., play/pause, skip forward/backward) andvolume controls, among other examples. Similar to the control device130, input to these playback controls are translated into playbackcommands via the software components 812 c and transmitted to one ormore playback devices 110 and/or 710 to control playback via the networkinterface 812 d.

In example implementations, the command device, as compared with thecontrol device(s) 130, is configured to control only paired and/orbonded playback devices, rather than the playback devices 110 a-n of themedia playback system 100 generally. For instance, in the FIG. 16Aexample in which the bridge device 860 a is paired with the portableplayback device 710 a, playback commands issued on the command device862 a are carried out on the portable playback device 710 a. Further,when the bridge device 860 a is bonded with one or more playback devices110, playback commands issued on the command device 862 a are alsocarried out on the bonded playback devices 110.

The user interface 813 a of the bridge device 860 a includes a dial 863a to facilitate volume control of paired playback device(s) 710 and/orbonded playback device(s) 110. In this example, the dial 863 a is formedby a first portion of the housing 816 a rotating about a base of thehousing 816 a, as illustrated in FIG. 16C. Clockwise andcounter-clockwise rotations of the dial 863 a correspond to upward anddownward volume adjustments.

The user interface 813 a of the bridge device 860 a also includes atouch-sensitive region 864 a to facilitate transport control of pairedplayback device(s) 710 and/or bonded playback device(s) 110, as shown inFIG. 16D. The touch-sensitive region 864 a is formed on the top surfaceof the housing 816 a, as shown in FIG. 16C. The touch-sensitive region864 a may be implemented as a capacitive or resistive touch-sensitiveregion, among other examples. In this example, a touch-input to thecenter of the touch-sensitive region 864 a is interpreted as aplay/pause toggle. The touch-sensitive region 864 a may also interpretcertain inputs as skip forward and backward. For instance, touch-inputsto the right and left sides of the touch-sensitive region 864 a may beinterpreted as a skip forward and skip backward, respectively.Alternatively, a left-to-right swipe gesture on the touch-sensitiveregion 864 a may be interpreted as a skip forward while a right-to-leftswipe gesture is interpreted as a skip forward.

In certain implementations, the user interface 813 a of the bridgedevice 813 a is intentionally limited to a certain subset of playbackcommands as compared with the “full-featured” control supported by thecontrol device(s) 130. As illustrated in FIGS. 16C and 16D, such asubset may include volume control and transport control (and perhapsonly certain transport controls). Such a simplified, minimalist userinterface may enhance the user experience of the paired playbackdevice(s) 710 or bonded playback device(s) 110 by reducing distraction,among other possible benefits.

In embodiments of the command device 862 a that exclude library and/orsearch controls to select audio content for playback, initiatingplayback via the command device 862 a may start a particular audiocontainer. The particular audio container may be pre-configured by theuser via the control device 130 or selected automatically by the mediaplayback system. Example audio containers include playlist, Internetradio stations, albums, and podcasts.

FIG. 16E is a front view of an example bridge device 860 b. In contrastto the circular housing 816 a of the bridge device 860 a, the housing816 b of the bridge device 860 b is more rectangular. A user interface813 b of the bridge device 860 b includes a dial 863 b on the frontsurface of the housing 816 b, a touch-sensitive region 864 b on the topsurface of the housing 816 b, as well as buttons 865 a-d on the frontsurface of the housing 816 b. Like the dial 863 a, the dial 863 bfacilitates volume control of portable playback devices 710 paired tothe bridge device 860 b and/or playback devices 110 bonded to the bridgedevice 860 b. Furthermore, the touch-sensitive region 864 b facilitatestransport control of paired portable playback devices 710 and/or bondedplayback devices 110 in a similar manner to the touch-sensitive region864 a.

The buttons 865 a-d correspond to respective audio containers. Theparticular audio containers may be pre-configured by the user via thecontrol device 130 or selected automatically by the media playbacksystem (e.g., based on user designated favorites or listeningfrequency). Selection of a particular button 865 causes the pairedplayback device 710 and/or bonded playback devices 110 to initiateplayback of the corresponding container, similar to how a radio presettunes a radio to a corresponding radio station.

For instance, selection of the button 865 a causes the bridge device 860b to send one or more instructions to the paired playback device 710 toplay back the audio container corresponding to the button 865 a. The oneor more instructions may include a URI indicating the location of theaudio container at a computing device 106 (e.g., a content server of astreaming audio service). The paired playback device 710 then streamsthe audio container from the computing device 106 and plays back thataudio container.

In some implementations, the bridge device 860 may include a graphicaldisplay. In such examples, the user interface 813 of the bridge device860 may include a graphical user interface displayed on thetouch-sensitive graphical display. In some examples, the graphicaldisplay is touch-sensitive to facilitate touch input to the graphicaluser interface. Yet, the graphical user interface may have limitedplayback controls as compared with the control devices 430 and 530,which may reduce distraction caused by the presence of the graphicaldisplay, among other possible benefits.

To illustrate, FIG. 17A presents a first user interface display 1770 aconfigured for display on a bridge device having a circulartouch-sensitive graphical display. For instance, an exampleimplementation of the bridge device 860 a may implement thetouch-sensitive region 864 a as a circular touch-sensitive graphicaldisplay. Other shapes and arrangements of touch-sensitive graphicaldisplays are contemplated as well.

The first user interface display 1770 a includes a plurality of regions1771 a-f, which are similar to the buttons 865 a-d (FIG. 8F). In thefirst user interface display 1770 a, the regions 1770 a-g are selectablevia touch input to the respective region. Each region 1771 correspondsto a respective audio container. The particular audio containers may bepre-configured by the user via the control device 130 or selectedautomatically by the media playback system (e.g., based on userdesignated favorites or listening frequency). Example audio containersinclude Internet radio stations, playlists, albums, podcasts, as well asother streaming audio content. Selection of a particular button 865causes the paired playback device 710 and/or bonded playback devices 110to initiate playback of the corresponding container.

Presently, by way of illustration, region 1770 a is shown in a centralposition in the first user interface display 1770 a. Regions 1771 b and1771 f are partially shown at bottom and top positions, respectively, inthe first user interface display 1770 a. By scrolling the first userinterface display 1770 a upwards or downwards using upwards or downwardsswipe gestures, respectively, regions 1771 b or 1771 f can be fullydisplayed and the regions 1771 c-e can be displayed as well in roundrobin fashion. To illustrate, FIG. 17B illustrates an upwards swipecausing the region 1771 b to move towards the central position. FIG. 17Cillustrates the region 1771 b in the central position after the upwardsswipe of FIG. 17B. As shown in FIG. 17C, regions 1771 a and 1771 c arepartially displayed when region 1771 b is in the central position.

When a particular region 1771 (e.g., region 1771 a) is selected, thebridge device 860 causes the paired playback device(s) 710 and/or bondedplayback device(s) 110 to initiate playback of the correspondingcontainer. When the region 1771 a is selected again while the containeris playing back, the bridge device 860 causes the paired playbackdevice(s) 710 and/or bonded playback device(s) 110 to stop playback ofthe corresponding container. In this manner, the regions 1771 functionas a play/pause button.

Other transport controls may be implemented by the graphical userinterface. For instance, as illustrated in FIG. 17C, swipe gestures inthe first user interface display 1770 a correlate to skip forward andskip backward. In particular, a swipe left may cause a skip forwardwhile a swipe right causes a skip backward.

FIG. 17D presents a second user interface display 1770 b, which may bedisplayed based on selection of region 1771 a. The second user interfacedisplay 1770 b includes a region 1772 that includes a graphicalrepresentation of audio content playing back on the paired playbackdevices 710 and/or bonded playback devices 110, as well as media contentinformation corresponding to the audio content. For instance, if theselected audio container is playing an audio track, metadatacorresponding to the audio track is displayed in region 1772.

The second user interface display 1770 b may also include one or moretransport controls. To illustrate, the second user interface display1770 b includes a jump forward control 1773 a and a jump backwardcontrol 1773 b. In various implementations, the second user interfacedisplay 1770 b may include other transport controls as well. Forinstance, swipe gestures in the second user interface display 1770 b maycorrelate to skip forward and skip backward, similar to the first userinterface display 1770 a.

The second user interface display 1770 b may further includenavigational controls. By way of example, the second user interfacedisplay 1770 b includes navigational controls 1774 a and 1774 b.Navigational control 1774 a causes the bridge device 860 to display thefirst user interface display 1770 a. Navigational control 1774 b causesthe bridge device 860 to display a third user interface display 1770 cincluding a queue.

To illustrate, FIG. 17E presents a third user interface display 1770 c,which may be displayed based on selection of navigational control 1774b. As shown, the third user interface display 1770 c includes aninterface to browse within the audio container. Selecting an individualaudio track or other media item within the audio container causesplayback of that media item. For instance, if the selected audiocontainer is a playlist, the third user interface display 1770 c liststhe audio tracks of the playlist. As another example, if the selectedaudio container is a podcast, the third user interface display 1770 cmay display other audio content available within that container (e.g.,episodes of a podcast).

In some implementations, the graphical user interface facilitatesselecting portable playback device(s) 710 to pair with the bridge device860 and/or playback device(s) 110 to bond with the command device 862.To illustrate, FIG. 17F presents a fourth user interface display 1770 dwith a plurality of toggle controls 1775 corresponding to respectiveportable playback devices 710 and zones. Toggling a toggle control 1775pairs or bonds the corresponding portable playback device(s) 710 orplayback device(s) 110 with the bridge device. As shown, the togglecontrol 1775 a corresponding to the headphones 710 a is toggled on suchthat the headphones 710 a are paired with the bridge device 860.

Selection of multiple zone names causes a zone group to be formedbetween the zones (if not already formed) and the bridge device 860 tobe paired with the zone group (and thereby control all playback devices110 in the zone group). Selection of the “Everywhere” toggle places themedia playback system 100 into party mode (in which all playback devices110 play music synchronously) and pairs the bridge device 860 with allplayback devices 110 in the media playback system 100.

Within example embodiments, the bridge device 860 charges one or morebatteries via placement on the device base 718. FIG. 18A illustratesplacement of the bridge device 860 a on a device base 718 b. The bridgedevice 860 a may interact with the device base 718 b in the same orsimilar manner as the portable playback device 710 c. For instance, ifthe device base 718 b is associated with a zone of the media playbacksystem 100, placement of the bridge device 860 a on the device base 718b causes the bridge device 860 a (and paired portable device(s) 710) tojoin the associated zone.

In example implementations, the bridge device 860 a is rotatable aboutthe device base 718 b to control volume of the portable playback device710 paired to the bridge device 860 a. In some implementations, rotationof the bridge device 860 a about the device base 718 b also controlsvolume of playback device(s) 110 bonded to the bridge device 860 a.Similar to the bridge device 718 a, the bridge device 860 a may rotatewith respect to the device base 718 b, which may generate a volumecontrol signal in a sensor of the bridge device 860 a and/or device base718 b. In another example, a first portion of the device base 718 b isrotatable with respect to a second portion of the device base 718 b.Rotation of these two portions generates a volume control signal in asensor of the device base 718 b that controls volume of the pairedplayback device 710 when the bridge device 860 a is placed upon thedevice base 718 b.

The bridge device(s) 860 of the media playback system 100 may also haveother features that support the portable device(s) 710 of the mediaplayback system. For instance, the bridge device(s) 860 may supportcharging the portable device 170. To illustrate, FIG. 18B illustrates anexample stacking arrangement that includes the device base 718 bcharging the bridge device 860 a, and the bridge device 860 a chargingthe earbuds 710 b via a charging case 1080. Similar to the device base718, the bridge device 860 a may charge the earbuds 710 b via inductivecharging or via conductive terminals. In some implementations, thedevice base 718 b may directly charge the earbuds 710 b via placement ofthe charging case 1080 on the device base 718 b. Other form factors ofthe charging case 1080 may be used to charge other form factors of theportable playback devices 710 (e.g., the headphones 710 a).

FIG. 18C illustrates another example stacking arrangement to facilitatedevice charging. In this example, the device base 718 a charges theportable playback device 710 c. The portable playback device 710 ccharges the bridge device 860 a. The bridge device 860 a charges theearbuds 710 b via a charging case 1080. In this arrangement, only thedevice base 718 a requires external power to charge the various stackeddevices.

X. Additional Swap Examples

In some examples, the source and target of a swap are pre-defined. In apre-defined swap pair, the source is the playback device 710 or the oneor more playback devices 110 that are playing audio content and thetarget is the other playback device that is not playing back audiocontent. Playback swapping between the source and targeted playbackdevices is performed when a swap trigger action such as a button pressor other user input is detected.

In some implementations, an input to the source device of a swap pairtriggers a swap. For instance, a particular input to user interface 713a of the headphones 710 (FIG. 7B) such as a tap or gesture to thetouch-sensitive region (or a portion thereof) may trigger the swap. Infurther examples, the portable playback device 710 may include aphysical button to trigger the swap. Yet further, a pattern oftouch-inputs (e.g. short, long, short) or a tracing pattern (e.g., ashape such as a zig-zag or triangle) may trigger a swap. Other types ofinputs are contemplated as well.

Additionally or alternatively, an input to the target device triggers aswap. For instance, a particular input to user interface 113 of theplayback device 110 a (FIG. 1C) may trigger the swap. In furtherexamples, the playback device(s) 110 may include a physical button totrigger the swap. Manipulating the button (e.g., by selecting, touching,sliding, etc.) triggers the swap. Other types of inputs are contemplatedas well.

Within examples, a user interface, such as the user interface 133 of thecontrol device 130 a, or the user interface 813 of the bridge device 860a, may facilitate defining a pre-defined swap pair. To illustrate, FIG.19A presents a first user interface display 1931 a to facilitatedefining a swap pair for the headphones 710 a (“Ben's Headphones”). Thefirst user interface display 1931 a is configured for display on thecontrol device 430 by way of example but may be adapted to be displayedon other example devices disclosed herein. The control device 430 maydisplay the first user interface display 1931 a during a set-upprocedure for the headphones 710 a. Further, the user may display thefirst user interface 1931 a via a settings user interface display, amongother examples.

As shown, the first user interface display 1931 a includes graphicalindications of the zones (i.e, zone names) within the media playbacksystem 100 and a toggle control corresponding to each zone. Toggling atoggle control configures the corresponding zone as a swap pair with theheadphones 710 a. In this example, the kitchen 101 h is defined as aswap pair with the headphones 710 c. While toggle controls are shown byway of example, other types of controls may be used in alternativeimplementations. Example user interfaces may include functionallysimilar user interface displays to define swap pairs for other portableplayback devices 710 of the media playback system 100 (e.g., the earbuds710 b and/or the portable playback device 710 c). Pre-defined swap pairsmay be stored in data storage of the control device(s) 130, the playbackdevice(s) and/or the portable playback devices 710, perhaps as one ormore state variables shared among these devices.

Alternatively, if the home graph hierarchy is implemented, a similaruser interface display may include graphical indications of the Sets,Rooms and/or Areas of the Home Graph configured in the media playbacksystem 100. This user interface display may include toggle controls orother similar controls corresponding to each Set, Room and/or Area. Inthis example, toggling a toggle control configures the correspondingSet, Room and/or Area as a swap pair with the headphones 710 a.

In some implementations, the media playback system 100 may define two ormore swap pairs for a portable playback device. To illustrate, FIG. 19Bpresents a second user interface display 1931 b to facilitate definingmultiple swap pairs for the earbuds 710 b. As shown, each pre-definedswap pair corresponds to a different input (e.g., a different gesture).Providing an input corresponding to a particular pre-defined swap pairtriggers a swap for that swap pair.

A user may define custom inputs corresponding to the pre-defined swappairs. To illustrate, FIG. 19C presents a third user interface display1931 c to facilitate defining a custom gesture. As shown, the third userinterface display 1931 c includes a prompt to provide a custom gesture.After pressing start, the earbuds 710 b and the playback devices 110 land 110 m in the swap pair monitor their respective user interfaces 713b and 113 to detect the custom input and then store the custom input indata storage.

In further examples, placement of a portable playback device 710 upon acharging base triggers a swap. For instance, placement of the portableplayback device 710 c upon the device base 718 a (FIG. 7F) may trigger aswap. In some implementations, the swap target is pre-defined for theportable playback device 710 c.

Alternatively, the device base 718 a may be bonded with one or moreparticular zones. Then, placement of the portable playback device 710 cupon the device base 718 a triggers a swap to the one or more particularzones. Additional details regarding bonding zones to a device base canbe found, for example, in U.S. Pat. No. 9,544,701 entitled, “BaseProperties in a Media Playback System,” which, as noted above, isincorporated herein by reference in its entirety.

In further examples, an input to a user interface of the device base 718a may trigger the swap. Example inputs include a button press (or othermanipulation) or a touch-input to a touch-sensitive region, similar tothe example inputs described above. For instance, a particular gesturemay be interpreted by the device base 718 a as a swap trigger.

In further examples, an input to the user interface 113 of the NMD 120 atriggers a swap. For instance, a user may speak a voice input as “swapto kitchen.” As described above in connection with FIGS. 3A-3D, a usermay activate a voice assistance service to process voice input with anactivation word or a button press (e.g., push-to-talk). This voice inputincludes a first command indicating the action (“swap”), and a secondcommand indicating the target playback device for the action(“kitchen”). Here, as described above in connection with FIGS. 3A-3D,the voice input is transmitted to the voice assistance service andprocessed. In some cases, the instructions corresponding to theprocessed voice commands are transmitted back to the source playbackdevice or target playback device to cause the playback session swap tobe performed. Alternatively, instructions corresponding to the processedvoice commands are transferred to a server to cause the playback sessionswap to be performed, as described in further detail below in connectionwith FIGS. 12B and 12C. Following the swap, the NMD 120 a may audiblyconfirm the swap with a voice response, such as “<audio content name> isnow playing in the kitchen.”

In some cases, both the source playback device and the target playbackdevice are playing audio content when a swap trigger is detected. Insuch examples, respective playback sessions of the source playbackdevice and the target playback device may be swapped, such that thesource playback device begins playing back audio content previouslyplaying on the target and the target begins playing back audio contentpreviously playing on the source. Alternatively, the playback session ofthe source playback device is swapped to the target playback device andplayback is stopped on the target.

Within example implementations, the source playback device mayfacilitate a swap by sending playback session data to the target device.The playback session data may include data representing a source of theaudio content (e.g., a URI or URL indicating the location of the audiocontent), as well as an offset indicating a position within the audiocontent to start playback. The offset may be defined as a time (e.g., inmilliseconds) from the beginning of the audio track or as a number ofsamples, among other examples. In example implementations, the offsetmay be set to a playback position in the audio content of the currentplayback position to allow time for the target device to start bufferingthe audio content. Then, the source playback device stops playback ofthe audio content at the offset and the target playback device startsplayback of the audio content at the offset.

The playback session data may further include one or more identifierscorresponding to the playback session. For instance, the playbacksession data may include a session identifier that distinguishes theplayback sessions from other playback sessions. The playback sessiondata may also include an application identifier identifying the mediaplayback system controller application software controlling the playbacksession. In addition, the playback session data may include a streamingaudio service identifier identifying the streaming audio service hostingthe audio content at the source, as well as an audio item identifier(e.g., a unique identifier used by the streaming audio service toidentify the audio content). As another example, a household identifiermay be included in the playback session data to distinguish the mediaplayback system 100 from other media playback systems. As a furtherexample, a group identifier may identify the device(s) in a zone, bondedzone, or zone group.

The playback session data may further include data representing playbackstate. Playback state may include a playback state of the session (e.g.,playing, paused, or stopped). If the playback session implements aplayback queue, the playback session data may include the playback queuestate, such as the current playback position within the queue.

The playback queue state may also include a queue version. For example,in a cloud queue embodiment, the cloud queue server and the mediaplayback system 100 may use the queue version to maintain consistency.The queue version may be incremented each time the queue is modified andthen shared between the media playback system 100 and cloud queue serverto indicate the most recent version of the queue.

Further, the playback session data may also include authorization data,such as one or more keys and/or tokens. Such authorization data mayinclude a token associated with the user account. During a playbacksession swap, the media playback system 100 may verify that the token isauthorized on both the source and target playback devices. Theauthorization data may further include a token associated with thestreaming audio service, which may enable the target playback device toaccess the audio content at the source. Yet further, the authorizationdata may include a token associate with the playback session, whichenables the target playback device to access the session. Other exampleauthorization data is contemplated as well.

To illustrate, FIG. 20A is an example message flow diagram showinginstructions exchanged between the source playback device, the targetplayback device, and a content server during an example swap of aplayback session. Such messages are representative and may includeadditional or fewer messages. In some implementations, rather than themessages being sent from a portable playback device 710 (as a source ortarget playback device), the messages are sent from a paired controldevice 130 a (FIG. 7G) or paired bridge device 860 a (FIG. 16A).

At 2081 a, the source playback device starts a playback session. Theplayback session may be initiated on the source playback device, thecontrol device 130, or the bridge device 860, among other examples. Insome cases, the playback session may include one or more additionalplayback devices playing back in synchrony with the source playbackdevice as part of a group.

At 2082 a, the source playback device detects the swap trigger, such asany of the example swap triggers described above, among other examples.In some cases, another device (e.g., the target playback device, thecontrol device 130, the device base 718, or the bridge device 860)detects the swap trigger and transmits data indicating that a swaptrigger was detected to the source playback device.

At 2083 a, the source playback device sends playback session data to thetarget playback device. As shown by way of example, the playback sessiondata includes data representing URI indicating a source of the currentlyplaying audio content in the session (e.g., the currently playing audiotrack). The playback session data also includes data representing anoffset in the audio content indicating a position in the audio contentto start playback. In addition, if the source playback device is playingback audio content from a queue, the playback session data may furtherinclude data representing the queue, which may include URIscorresponding to respective media items in the queue, as well as anorder of the queued media items. Further, the playback session dataincludes one or more identifiers, as described above.

At 2084 a, the target playback device sends a fetch message to thecontent server to request a stream of the audio content from the contentserver. The fetch message may include a URI indicating the source of theaudio content at the content server. The fetch message may furtherinclude an offset. The fetch message may include other data as well,such as one or more identifiers and/or authorization data.

Based on this fetch message, at 2085 a, the content server streams theaudio content to the target playback device for playback. The contentservice may begin the stream at the offset in the audio content. Thetarget playback device then begins playing back the audio content at theoffset in the audio content.

At 2086 a, the target playback device sends an acknowledge message tothe source playback device after receiving the playback session data. Inexample implementations, the source playback device might not stop theplayback session until receiving the acknowledge message from the targetplayback device. The acknowledgement message may indicate that the swapwas successful.

Other example implementations utilize a cloud queue to facilitate theplayback session swap. In contrast to a queue in data storage of theplayback devices 110 (i.e., a local queue), a cloud queue for a playbacksession is maintained in the cloud on a computing device 106. In thisimplementation, rather than controlling the playback devices 110 a-nlocally via the networks 104, the control device 130 a controls theplayback devices 110 a-n via the computing device 106 by manipulatingthe cloud queue on the computing device 106. The computing device 106synchronizes the cloud queue (or a portion thereof) with the playbackdevice(s) 110 participating in the playback session.

To illustrate, FIG. 20B is an example message flow diagram showinginstructions exchanged between the source playback device, a cloud queueserver, the target playback device, and a content server during anexample swap of a playback session. Such messages are representative andmay include additional or fewer messages. In some implementations,rather than the messages being sent from a portable playback device 710(as a source or target playback device), the messages are sent from apaired control device 130 a (FIG. 7G) or paired bridge device 860 a(FIG. 16A).

At 2081 b, the source playback device starts a playback session. Theplayback session may be initiated on the source playback device, thecontrol device 130, or the bridge device 860, among other examples. Insome cases, the playback session may include one or more additionalplayback devices playing back in synchrony with the source playbackdevice as part of a group.

At 2082 b, the source playback device detects the swap trigger, such asany of the example swap triggers described above, among other examples.In some cases, another device (e.g., the target playback device, thecontrol device 130, the device base 718, or the bridge device 860)detects the swap trigger and transmits data indicating that a swaptrigger was detected to the source playback device.

At 2087, the source playback device sends a swap session message to thecloud queue server that includes playback session data. The swap sessionmessage may indicate the target playback device via one or moreidentifiers. In some examples, such as with a pre-defined swap pair, thecloud queue server may maintain the pre-defined swap pairs for the mediaplayback system 100. The swap session message may also include datarepresenting an offset in the audio content indicating a position in theaudio content to start playback. Within examples, the cloud queue servermay also track play position in the playback session and may use theposition in the swap session message to verify play position. Yetfurther, the swap session message may include a household identifieridentifying the media playback system 100 (so as to distinguish fromother media playback systems in other households) as well as one or moreplayer identifiers to identify the source and/or target playbackdevices.

Based on receiving the swap session message, the cloud queue serverre-targets the session from the source device to the target device. Forinstance, the cloud queue server may use a household identifier in theplayback session data to identify cloud queues of the media playbacksystem 100 and then use the group identifier (or a queue identifier) toidentify the cloud queue utilized in the playback session. The cloudqueue server may swap this session to the target playback devicesaltering the cloud queue data to associate the cloud queue with thetarget playback device. Alternatively, the cloud queue server may mirrorthe cloud queue of the source device with a cloud queue of the targetplayback device, then set the playback state of this cloud queue tomatch the playback state indicated in the playback session data.

For instance, at 2088, the cloud queue server sends playback sessiondata to the target playback device. The playback session data includesdata representing URI indicating a source of the currently playing audiocontent in the session (e.g., the currently playing audio track). Theplayback session data also includes data representing an offset in theaudio content indicating a position in the audio content to startplayback. In addition, if the source playback device is playing backaudio content from a cloud queue with multiple audio, the playbacksession data may further include data representing a window from thecloud queue. The window may indicate media items subsequent to thecurrently playing audio content as well as possibly media items beforethe currently playing audio content. The target playback device mayqueue this window in a local queue to facilitate further playback of thecloud queue in the transferred session

At 2084 b, the target playback device sends a fetch message to thecontent server to request a stream of the audio content from the contentserver. Based on this fetch message, at 2085 b, the content serverstreams the audio content to the target playback device for playback.The target playback device then begins playing back the audio content atthe offset in the audio content.

FIG. 20C is an example message flow diagram showing instructionsexchanged between the source playback device, the target playbackdevice, and one or more servers (e.g., the cloud queue server and/or thecontent server, which may be implemented by one or more cloud servers)during another example swap of a playback session. Such messages arerepresentative and may include additional or fewer messages. In someimplementations, rather than the messages being sent from a portableplayback device 710 (as a source or target playback device), themessages are sent from a paired control device 130 a (FIG. 7G) or pairedbridge device 860 a (FIG. 16A).

At 2081 c, the source playback device starts a playback session. Theplayback session may be initiated on the source playback device, thecontrol device 130, or the bridge device 860, among other examples. Insome cases, the playback session may include one or more additionalplayback devices playing back in synchrony with the source playbackdevice as part of a group.

At 2082 c, the source playback device detects the swap trigger, such asany of the example swap triggers described above, among other examples.In some cases, another device (e.g., the target playback device, thecontrol device 130, the device base 718, or the bridge device 860)detects the swap trigger and transmits data indicating that a swaptrigger was detected to the source playback device.

At 2083 b, the source playback device sends playback session data to thetarget playback device. The playback session data includes one or moreidentifier, such as a playback session identifier and a queueidentifier. The playback session data may also include a URI indicatingthe source of the audio content, as well as an offset within thatcontent.

At 2089, the target playback device sends a swap session request to theone or more servers. In a cloud queue implementation, the swap sessionrequest may be in the form of a load queue request indicatinginstructions to load the current cloud queue state of the cloud queuebeing played back by the source playback device onto the target playbackdevice. To facilitate such requests, the swap session request includesone or more identifiers corresponding to the playback session (e.g., ahousehold identifier, a playback device identifier of the target device,a queue identifier, a playback session identifier).

Upon receiving the swap session request, the one or more serversfacilitate streaming the audio content to the target playback device.For instance, the one or more servers (the content server) may create anew session on the target playback device, such as by instructing acloud queue server to create a new session on the target playbackdevice. This request may include the household identifier, applicationidentifier, and user account, as well as other identifiers. The playbacksession data may be used to mirror the playback session on the sourceplayback device in the new session on the target playback device.

At 2085 c, the content server streams the audio content to the targetplayback device for playback. The content service may begin the streamat the offset in the audio content. The target playback device thenbegins playing back the audio content at the offset in the audiocontent.

At 2086 b, the target playback device sends an acknowledge message tothe source playback device after receiving the playback session data. Inexample implementations, the source playback device might not stop theplayback session until receiving the acknowledge message from the targetplayback device. The acknowledgement message may indicate that the swapwas successful.

In further examples, the source and target playback devices perform aswap by forming a synchrony group. As noted above, example playbackdevice(s) 110 and/or playback device(s) 710 may dynamically form andde-form synchrony groups. As noted above, additional details regardingaudio playback synchronization among playback devices and/or zones canbe found, for example, in U.S. Pat. No. 8,234,395 entitled, “System andmethod for synchronizing operations among a plurality of independentlyclocked digital data processing devices,” which has been incorporatedherein by reference in its entirety.

In some implementations, the source playback device forms a synchronygroup with the target playback device and then mutes its output. Whenthe synchrony group is formed, the target playback device begins playingback the audio content of a given session in synchrony with the sourcedevice. To complete the “swap,” the source device is muted. From theuser's perspective, the playback session appears swapped even thoughboth the source and target playback devices are participating in thesession. This mute can be a hidden (e.g., system) mute that is differentfrom a mute command via a user interface. A hidden mute may be performedby lowering the volume or setting the volume to zero on the sourcedevice while displaying on the user interface that the source device isunmuted and playback is paused.

To swap playback back to the source playback device, the target playbackdevice is removed from the synchrony group. A possible advantage of thisimplementation is that the session can be swapped back to the sourcedevice with relatively no delay, as the audio content does not need tore-buffer. Another possible advantage of this implementation is that thesource playback device maintains control of the audio stream.

In further examples, detecting proximity between the source playbackdevice and the target playback device triggers a swap. For instance,detecting that a source playback device and a target playback device ofa pre-defined swap pair are in proximity may initiate a swap of aplayback session between the source playback device and the targetplayback device. In some implementations, the source and target playbackdevices of a swap are defined by proximity of the source playback deviceto the target playback device. Example proximity detection may beimplemented at one or more ranges, such as proximity to the mediaplayback system 100 (i.e., the home or some other known location),proximity to a zone, or proximity to a playback device.

For instance, in some implementations, proximity of the portableplayback device 710 to the media playback system 100 initiates aplayback session swap with one or more target playback devices 110within the home. In an example, upon a user returning home with theportable playback device 710, the paired control device 130 a (FIG. 7G),or the paired bridge device 860 (FIG. 16A), proximity of the portableplayback device 710 to the media playback system 100 is detected via asensor or wireless communications interface of the portable playbackdevice 710, the paired control device 130 a (FIG. 7G), or the pairedbridge device 860 (FIG. 16A). This proximity detection initiates aplayback session swap between the portable playback device 710 and oneor more target playback devices 110 within the home.

To illustrate, in example implementations, the paired control device 130a (FIG. 7G) detects a wireless signal that indicates proximity of theportable playback device 710 to the playback devices 110. For instance,the paired control device 130 a (FIG. 7G) may detect (e.g., connect to)an 802.11 network (e.g., the network 104) within the home via thenetwork interfaces 132 d. Since the playback devices 110 a-n areconnected to the network 104, detection of this network indicates thatthe paired control device 130 a (and by proxy, the paired portableplayback device 710) is in proximity to the home. Other example wirelesssignals include near-field communication (NFC) and 802.15 (Bluetooth®,Bluetooth® Low Energy) signals which may be transmitted by the playbackdevices 110 a-n within the home. In other examples, the paired bridgedevice 860 (FIG. 16A) may detect such signals or the portable playbackdevice 710 may detect the signals directly via their respective networkinterface(s).

Alternatively, the paired control device 130 a (FIG. 7G) detectsproximity to the playback devices 110 a-n via one or more sensors. Forinstance, the paired control device 130 a may include a GPS sensor andcompare current GPS coordinates to stored GPS coordinates of the home(or other known location of the playback devices 110 a-n) to determinewhether the paired control device 130 a is in proximity to this storedlocation. In further examples, the paired control device 130 a maydetect proximity by using a microphone to detect ultrasonic tones (orother signals) emitted by one or more of the playback devices 110 a-n.Alternatively, the paired control device 130 a may utilize a camera todetect known objects or signals within the home. Other examples arepossible as well.

In some examples, prior to performing a playback session swap based onproximity, verification is required from the user. In some examples,verification is implemented via an input to a user interface on thesource portable playback device 710 (or a paired control device 130 orbridge device 860 a). For instance, verification may be implemented viaa push notification (or other prompt, such as a widget) displayed on thepaired control device 130 a. To illustrate, FIG. 21A presents a firstuser interface display 2131 a that includes an example push notification2191 a. The paired control device 130 a may display the first userinterface display 2131 a based on detecting proximity to the playbackdevice(s) 110 a-n.

As shown in FIG. 21A, the push notification 2191 a of the first userinterface display 2131 a includes multiple selectable controls. A firstselectable control (“Swap”) causes the paired control device 130 a toperform a playback session swap between the headphones 710 a (“Ben'sHeadphones”) with the kitchen 101 h, which may be a pre-defined swappair (FIG. 11A) or the nearest playback device 110, among otherexamples. A second selectable control (“Cancel”) cancels theproximity-based swap.

Also shown in FIG. 21A are selectable controls 2192 a and 2193 b. Ratherthan transferring an in-progress playback session, selectable control2192 a causes the kitchen 101 h to continue a stopped playback session(e.g., playback of a podcast). In example implementations, selectablecontrol 2192 a may represent the last-stopped playback session on theportable playback device 710 a, the last-stopped playback session in thekitchen 101 h, or the last stopped playback session in the mediaplaybacks system 100, among other examples. Alternatively, the pushnotification 2191 a may include multiple selectable controls 2192 toselect different last-stopped playback sessions.

Selectable control 2193 a causes the kitchen 101 h to start a newplayback session that includes playback of a given playlist. In variousimplementations, example push notifications 2191 may include selectablecontrol 2193 to start new playback sessions with various types of audiocontainers corresponding to the user. For instance, respectiveselectable controls 2193 may start new playback sessions with favoriteplaylists, radio stations, podcasts, albums, or artists, among otherexamples, similar to the buttons 865 (FIG. 16E) and/or the regions 1771(FIG. 17A).

As further shown in FIG. 21A, a third selectable control of the pushnotification 2191 a causes display of a user interface display to selecta different swap target. To illustrate, FIG. 21B presents a second userinterface display 2131 b to facilitate selecting a swap target. The userinterface display 2131 b includes a plurality of toggle controlscorresponding to respective zones of the media playback system 100 tofacilitate selecting one or more target playback devices 110 n.

In some implementations, proximity of the portable playback device 710to a zone initiates a playback session swap with the playback device(s)110 within that zone. Detecting that the portable playback device 710 isin proximity to a given zone may involve detecting a signal (e.g.,wireless, ultrasonic) emitted by the playback devices within that zone.In some implementations, detecting signals emitted by other smartdevices within the zone may indicate proximity.

For example, the paired control device 130 a may determine a profilecorresponding to one or more zones. For instance, while in the kitchen101 h, the paired control device 130 a may detect a signal emitted bythe playback device 110 b, as well as other smart devices (e.g., a smartoven, a smart fridge, a smart power outlet) and save these signals asmarkers for the kitchen 101 h in a profile corresponding to the kitchen101 h. Further, the paired control device 130 a may combine this signaldata with other sensor data (such as altitude) captured while in thekitchen 101 h. The markers in a given profile may also be weighted(e.g., signals of a playback device in a given zone may be weighted moreheavily than other smart devices within that zone).

Given stored profiles for multiple zones in the media playback system100, to detect whether the portable playback device 710 is in proximityto a given zone, the paired control device 130 a may compare currentsignals and/or sensor data to the stored profile(s) corresponding to thezones. For instance, the paired control device 130 a may determine theclosest match to the current signals and/or sensor data by comparing howmany markers in each profile are present in the current signals and/orsensor data. The paired control device 130 a may also threshold themarkers by determining proximity to a particular zone when apre-determined number (or percentage) of markers in the stored profileof the particular zone are also present in the current signals and/orsensor data. While these operations are described by example as beingperformed by the paired control device 130 a, other devices such as theportable playback device 710 and/or the bridge device 860 may alsodetermine the profile and/or detect proximity using the stored profiles.

Additional techniques to facilitate determining zone proximity can befound, for example, in U.S. Patent App. Pub. No. 2016/0062606 A1entitled, “Zone Recognition,” which is incorporated herein by referencein its entirety.

Similar to proximity to the home, prior to performing a playback sessionswap to a zone based on proximity, the media playback system 100 mayrequest verification that the user intends a swap to be performed. Toillustrate, FIG. 21C presents a third user interface display 2131 c thatincludes an example push notification 2191 b. The paired control device130 a may display the third user interface display 2131 c based ondetecting proximity to the Den 101 d.

In further examples, proximity to a given zone is determined via a userinput to a playback device of that zone. For instance, a particular userinput to the playback device 710 (or paired control device 130 a orbridge device 860 a) may initiate a playback session swap with theplayback device 710 as the source playback device. Then, a user input toa given playback device 110 selects that playback device (or associatedzone) as the target playback device(s). The source and target playbackdevices may be configured to perform a swap on the condition that thesecond input is detected within a pre-determined period of time (e.g., 5seconds) following the first input, so as to indicate proximity betweenthe source and target playback devices.

In further examples, another trigger, such as a button press, initiatesplayback session swap to target playback devices with proximity to asource playback device. To illustrate, FIG. 22A illustrates an exampleplayback session swap between the portable playback device 710 c and theplayback device 110 e, which is in proximity to the portable playbackdevice 710 c. As shown, a particular swap input (e.g., a long press tothe user interface 713 c) triggers a playback session swap. In thisexample, the source playback device (i.e., the portable playback device710 c) is identified via the particular swap input. The target playbackdevice (i.e., the playback device 110 e) is identified via proximitydetection by the portable playback device.

As another example, FIG. 14B illustrates an example playback sessionswap between the headphones 710 a and the playback device 110 e, whichis in proximity to the portable playback device 710 a. As shown, ahold-close action triggers a playback session swap. In this example, thesource playback device (i.e., the headphones 710 a) and the targetplayback device (i.e., the playback device 110 e) are both identified bythe hold-close action, which causes a near-field communication exchangebetween the headphones 710 a and the playback device 110 e. Sincenear-field communication has a limited range (e.g., 4 cm), thenear-field communication exchange indicates proximity between theheadphones 710 a and the playback device 110 e.

As a further example, FIG. 22C illustrates an example playback sessionswap between the earbuds 710 b and the playback device 110 e. In thisexample, a hold close action by the control device 130 a (paired to theearbuds 710 b) triggers a playback session swap. In this example, thesource playback device (i.e., the earbuds 710 b) and the target playbackdevice (i.e., the playback device 110 e) are both identified by thehold-close action, which causes a near-field communication exchangebetween the paired control device 130 a and the playback device 110 e.

In another example, FIG. 22D illustrates another example playbacksession swap between the earbuds 710 b and the playback device 110 e. Inthis example, a hold close action by the bridge device 860 a (paired tothe earbuds 710 b) triggers a playback session swap. In this example,the source playback device (i.e., the earbuds 710 b) and the targetplayback device (i.e., the playback device 110 e) are both identified bythe hold-close action, which causes a near-field communication exchangebetween the paired bridge device 860 a and the playback device 110 e.

In some instances, the target playback device(s) are members of asynchrony group such as a bonded zone (e.g., a stereo pair such as themaster bedroom 101 b or a surround sound configuration such as the den101 d) or a zone group (e.g., a “Kitchen+Dining Room” zone group). Asnoted above, example synchrony techniques involve a group coordinatorproviding audio content and timing information to one or more groupmembers to facilitate synchronous playback among the group coordinatorand the group members. In such examples, a target playback device mightbe a group coordinator (that provides audio content and timinginformation to the group members) or a group member (that receives audiocontent and timing information from the group coordinator).

In example implementations, when a group coordinator is designated asthe target playback device, the group coordinator may, as a result ofthe synchrony group arrangement, automatically “take along” groupmembers during a playback session swap by providing the group membersaudio content and timing information corresponding to the swappedplayback session. That is, since the group members receive the audiocontent and timing information from the group coordinator, when thegroup coordinator starts playing back the swapped playback session, thegroup members start playing back the swapped playback session as well.

Generally, when initiating a playback session swap via a GUI of thecontrol device 130 a or VUI of the NMD 120 a, the bonded zone or zonegroup is targeted as a whole by reference to the name of the bondedzone, the zone group, or a member zone. In a local implementation, thecontrol device 130 a or the NMD 120 a may transmit one or more messagesto the group coordinator indicating the playback session swap, whichthen performs the swap. In a cloud implementation, the control device130 a or the NMD 120 a may transmit one or more messages to the cloudqueue server indicating the playback session swap to cause the cloudqueue server to perform the swap or to relay instructions to the groupcoordinator to perform the playback session swap.

In other cases, a group member is targeted for a swap (e.g., byproviding input indicating a swap command to the user interface of thegroup member). In a local implementation, the group coordinator cantransmit one or more messages indicating the swap command to the groupcoordinator, which then performs the playback session swap. In a cloudimplementation, the group member may transmit one or more messages tothe cloud queue server indicating the playback session swap to cause thecloud queue server to perform the swap or to relay instructions to thegroup coordinator to perform the playback session swap. Alternatively,the group member may transmit one or more messages to the groupcoordinator indicating the playback session swap, which cause the groupcoordinator to transmit a playback session swap request to the cloudserver.

XI. Additional Portable Playback Device Examples

FIG. 23A is a front isometric view of earbuds 2310 including an earbud2310 a and an earbud 2310 b configured in accordance with aspects of thedisclosed technology. As shown, the earbuds 2300 are carried in acharging case 2380.

FIG. 23B is a bottom view of the charging case 2380.

FIG. 23C is a top view of the charging case 2380.

FIG. 23D is a first side view of the charging case 2380.

FIG. 23E is a second side view of the charging case 2380.

FIG. 23F is a front isometric view of the earbud 2310 a and the earbud2310 b illustrating exemplary arrangement with the charging case 2380.

FIG. 23F is an isometric view of the earbud 2310 a.

FIG. 23H is a first side view of the earbud 2310 a.

FIG. 23I is a second side view of the earbud 2310 a.

FIG. 23J is a third side view of the earbud 2310 a.

FIG. 23K is a fourth side view of the earbud 2310 a.

FIG. 23L is a fifth side view of the earbud 2310 a.

FIG. 23M is a sixth side view of the earbud 2310 a.

FIG. 24A is a front isometric view of a portable playback device 2410implemented as a handheld speaker configured in accordance with aspectsof the disclosed technology.

FIG. 24B is a side view of the portable playback device 2410.

FIG. 24C is a top view of the portable playback device 2410.

FIG. 24D is a bottom view of the portable playback device 2410.

FIG. 24E is a front isometric view of the portable playback device 2410illustrating exemplary arrangement with a device base 2418.

FIG. 24F is a front isometric view of the portable playback device 2410illustrating exemplary user inputs to the portable playback device 2410.

FIG. 25A is a front view of headphones 2510 configured in accordancewith aspects of the disclosed technology.

FIG. 25B is a first side view of the headphones 2510.

FIG. 25C is a second side view of the headphones 2510.

FIG. 26A is a front view of headphones 2610 configured in accordancewith aspects of the disclosed technology.

FIG. 26B is a first side view of the headphones 2610.

FIG. 26C is a second side view of the headphones 2610.

XII. Conclusion

The above discussions relating to portable playback devices, playbackdevices, control devices, playback zone configurations, and mediacontent sources provide only some examples of operating environmentswithin which functions and methods described below may be implemented.Other operating environments and configurations of media playbacksystems, playback devices, and network devices not explicitly describedherein may also be applicable and suitable for implementation of thefunctions and methods.

The description above discloses, among other things, various examplesystems, methods, apparatus, and articles of manufacture including,among other components, firmware and/or software executed on hardware.It is understood that such examples are merely illustrative and shouldnot be considered as limiting. For example, it is contemplated that anyor all of the firmware, hardware, and/or software aspects or componentscan be embodied exclusively in hardware, exclusively in software,exclusively in firmware, or in any combination of hardware, software,and/or firmware. Accordingly, the examples provided are not the onlyways) to implement such systems, methods, apparatus, and/or articles ofmanufacture.

Additionally, references herein to “embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment can be included in at least one example embodiment of aninvention. The appearances of this phrase in various places in thespecification are not necessarily all referring to the same embodiment,nor are separate or alternative embodiments mutually exclusive of otherembodiments. As such, the embodiments described herein, explicitly andimplicitly understood by one skilled in the art, can be combined withother embodiments.

The specification is presented largely in terms of illustrativeenvironments, systems, procedures, steps, logic blocks, processing, andother symbolic representations that directly or indirectly resemble theoperations of data processing devices coupled to networks. These processdescriptions and representations are typically used by those skilled inthe art to most effectively convey the substance of their work to othersskilled in the art. Numerous specific details are set forth to provide athorough understanding of the present disclosure. However, it isunderstood to those skilled in the art that certain embodiments of thepresent disclosure can be practiced without certain, specific details.In other instances, well known methods, procedures, components, andcircuitry have not been described in detail to avoid unnecessarilyobscuring aspects of the embodiments. Accordingly, the scope of thepresent disclosure is defined by the appended claims rather than theforegoing description of embodiments.

When any of the appended claims are read to cover a purely softwareand/or firmware implementation, at least one of the elements in at leastone example is hereby expressly defined to include a tangible,non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on,storing the software and/or firmware.

Example 1: A method comprising: while a first playback device is playingback audio content during a playback session, detecting a playbacksession swap trigger corresponding to the playback session; determining(a) one or more source playback devices, the one or more source playbackdevices comprising the first playback device and (b) one or more targetplayback devices comprising a second playback device; and based on theplayback session swap trigger, transitioning the playback session fromthe determined one or more source playback devices to the one or moretarget playback devices.

Example 2: The method of example 1, wherein transitioning the playbacksession from the determined one or more source playback devices to theone or more target playback devices comprises: forming a synchrony groupthat includes the first playback device and the second playback devicesuch that the first playback device and the second playback device playback the audio content in synchrony; and muting the first playbackdevice.

Example 3: The method of example 1 or 2, wherein transitioning theplayback session form the determined one or more source playback devicesto the one or more target playback devices comprises: transmitting, to acloud queue server, instructions to transfer the playback session fromthe first playback device to the second playback device, wherein thecloud queue server transfers the playback session to the second playbackdevice based on the instructions.

Example 4: The method of any preceding example, wherein transitioningthe playback session from the determined one or more source playbackdevices to the one or more target playback devices comprises:transmitting, to the second playback device, data representing (i) anuniform resource identifier (URI) indicating a source of the audiocontent and (ii) an offset within the audio content, wherein the secondplayback device streams the audio content from the source of the audiocontent and plays back the audio content beginning at the offset, andwherein the first playback device stops playing back the audio contentat the offset.

Example 5: The method of any preceding example, wherein the firstplayback device comprises: at least one processor; data storage; one ormore amplifiers; one or more transducers; one or more batteriesconfigured to drive the one or more amplifiers and the one or moretransducers; and one or more housings carrying the at least oneprocessor, the data storage, the one or more amplifiers, the one or moretransducers, and the one or more batteries, wherein the one or morehousings are formed into at least one of (a) headphones or (b) earbuds.

Example 6: The method of any preceding example, wherein the firstplayback device is paired, via a first type of wireless connection, to acontrol device, and wherein the first playback device is connected tothe second playback device via the first type of wireless connection anda second type of wireless connection between the control device and thesecond playback device.

Example 7: The method of any preceding example, wherein detecting theplayback session swap trigger comprises: detecting, via a user interfaceof the control device, input representing a command to swap the playbacksession.

Example 8: The method of any preceding example, wherein detecting theinput representing the command to swap the playback session comprises:detecting a touch-and-hold input to a touch-sensitive region on thefirst playback device, wherein a touch input performs a first actionthat is not a swap.

Example 9: The method of any preceding example, wherein detecting theinput representing the command to swap the playback session comprises:detecting a touch-and-continued hold input to a touch-sensitive regionon the first playback device, wherein a touch input performs a firstaction and a touch-and-hold performs a group action, and wherein thefirst action is not a swap.

Example 10: The method of one of examples 1-5, wherein the firstplayback device is paired, via a first type of wireless connection, to abridge device, and wherein the first playback device is connected to thesecond playback device via the first type of wireless connection and asecond type of wireless connection between the bridge device and thesecond playback device.

Example 11: The method of example 10, wherein detecting the playbacksession swap trigger comprises: detecting, via a user interface of thebridge device, input representing a command to swap the playbacksession.

Example 12: The method of example 10 or 11, wherein the bridge devicecomprises a circular housing, and wherein the method further comprises:detecting a rotation of the circular housing; and adjusting a playbackvolume of the first playback device in proportion to the rotation.

Example 13: The method of one of examples 1-12, wherein the firstplayback device comprises: at least one processor; data storage; one ormore amplifiers; one or more transducers; one or more batteriesconfigured to drive the one or more amplifiers and the one or moretransducers; and a housing carrying the at least one processor, the datastorage, the one or more amplifiers, the one or more transducers, andthe one or more batteries, wherein the housing is formed into a handheldspeaker.

Example 14: The method of example 13, wherein detecting the playbacksession swap trigger comprises: detecting that the housing is placedinto a device base.

Example 15: The method of any preceding example, wherein the secondplayback device excludes a battery and draws current from wall power.

Example 16: The method of any preceding example, wherein the detectingthe playback session swap trigger comprises: detecting proximity of thesecond playback device to the first playback device.

Example 17: The method of any preceding example, wherein determining theone or more target playback devices comprises: detecting proximity ofthe second playback device to the first playback device.

Example 18: The method of any preceding example, wherein the one or moretarget playback devices further comprise a third playback device, andwherein determining the one or more target playback devices comprises:determining that the third playback device is configured into asynchrony group with the second playback device.

Example 19: A system configured to perform the method of any of examples1-18.

Example 20: A device configured to perform the method of any of examples1-18.

Example 21: A tangible, non-transitory computer-readable media havingstored therein instructions executable by one or more processors toperform the method of any of examples 1-18.

Example 22: A portable playback device comprising: at least oneprocessor; a network interface; one or more amplifiers; one or moretransducers; one or more batteries configured to drive the one or moreamplifiers and the one or more transducers; and one or more housingsformed into (a) earbuds or (b) headphones, the one or more housingscarrying the at least one processor, the network interface, the one ormore amplifiers, the one or more transducers, and the one or morebatteries, and data storage having stored therein instructionsexecutable by one or more processors to perform the method of any ofexamples 1-18.

Example 23: A method involving a wearable device, the method comprising:receiving data representing a first playback session swap input; basedon receiving the data representing the first playback session swapinput, identifying one or more source playback devices within a mediaplayback system that are (a) connected to a first wireless local areanetwork (LAN) and (b) playing back particular audio content in aplayback session, wherein the wearable playback device is connected tothe first wireless LAN via a 802.11-compatible network interface; andtransitioning the playback session from the determined one or moresource playback devices to the wearable playback device, whereintransitioning the playback session comprises (i) forming a firstsynchrony group including the wearable playback device and the one ormore source playback devices, wherein forming the first synchrony groupcauses the wearable playback device to start playing the particularaudio content of the playback session, and (ii) causing playback of theparticular audio content on the one or more source playback devices tostop.

Example 24: The method of example 23, wherein identifying the one ormore source playback devices comprises: identifying a set ofswap-eligible playback devices in the media playback system; causing theset of swap-eligible playback devices to emit respective audio chirpsthat identify the emitting swap-eligible playback devices; detecting,via one or more microphones, the audio chirps emitted by one or moreswap-eligible playback devices; and selecting the one or more sourceplayback devices from among the one or more swap-eligible playbackdevices based on the audio chirp from the one or more source playbackdevices indicating that the one or more source playback devices arephysically nearest to the wearable playback device among the one or moreswap-eligible playback devices.

Example 25: The method of example 24, wherein the one or moremicrophones comprise one or more acoustic noise cancelling microphonescarried on one or more exterior surfaces of the one or more wearablehousings, and wherein detecting the audio chirps emitted by one or moreswap-eligible playback devices comprises: detecting the audio chirpsemitted by one or more swap-eligible playback devices via the one ormore acoustic noise cancelling microphones.

Example 26: The method of any preceding example 23-25, wherein selectingthe one or more source playback devices from among the one or moreswap-eligible playback devices comprises: comparing one or morerespective metrics of the detected audio chirps emitted by one or moreswap-eligible playback devices to determine that the one or more sourceplayback devices are physically nearest to the wearable playback deviceamong the one or more swap-eligible playback devices.

Example 27: The method of any preceding example 23-26, furthercomprising: while playing back audio content in the transitionedplayback session, receiving data representing a second playback sessionswap input; based on the second playback session swap input, identifyingone or more target playback devices within the media playback systemthat are connected to the first wireless LAN; and transitioning theplayback session from the determined one or more target playback devicesto the wearable playback device, wherein transitioning the playbacksession comprises (i) forming a second synchrony group including thewearable playback device and the one or more target playback devices,wherein forming the second synchrony group causes the one or more targetplayback devices to start playing the particular audio content of theplayback session, and (ii) removing the wearable playback device fromthe second synchrony group.

Example 28: The method of any preceding example 23-27, wherein one ormore wearable housings of the wearable playback device comprise atouch-sensitive region, and wherein receiving the data representing theplayback session swap input comprises receiving input data representinga touch-and-hold input on the touch-sensitive region.

Example 29: The method of any preceding example 23-28, wherein receivingthe data representing the playback session swap input comprisesreceiving, via the 802.11-compatible network interface from a controllerapplication on a mobile device, data representing instructions toperform a playback session swap.

Example 30: The method of any preceding example 23-29, wherein causingplayback of the particular audio content on the one or more sourceplayback devices to stop comprises: after forming the synchrony groupincluding the wearable playback device and one or more source devices,causing the one or more source devices to be removed from the synchronygroup.

Example 31: The method of any preceding example 23-30, wherein the oneor more source devices comprises a master playback device configured toplay back multi-channel audio, and wherein transitioning the playbacksession comprises: sending, via the 802.11-compatible network interfaceto the master playback device, data representing instructions to enter aswap mode; sending, via the 802.11-compatible network interface to themaster playback device, data representing instructions to enter a swapmode; disconnecting from the first wireless LAN and connecting to thesecond wireless LAN via the 802.11-compatible network interface; andwhile connected to the second wireless LAN, receiving, via the802.11-compatible network interface, data representing (i) playbacktiming information for the first synchrony group and (ii) themulti-channel audio.

Example 32: The method of any preceding example 23-31, wherein thewearable playback device comprises: one or more network interfaces,wherein the one or more network interfaces comprises an802.11-compatible network interface; one or more transducers; one ormore amplifiers configured to drive the one or more transducers; one ormore batteries; one or more processors; one or more wearable housings,the one or more wearable housings carrying the one or more networkinterfaces, the one or more transducers, the one or more amplifiers, theone or more batteries, the one or more processors, and data storagehaving instructions stored thereon that are executable by the one ormore processors to cause the wearable playback device to perform themethod of any preceding example 23-31.

Example 33: The method of example 32, wherein one or more wearablehousings of the wearable playback device are formed into one of (a)headphones or (b) one or more earbuds.

Example 34: A system configured to perform the method of any of examples23-32.

Example 35: A device configured to perform the method of any of example23-32.

Example 36: A tangible, non-transitory computer-readable media havingstored therein instructions executable by one or more processors toperform the method of any of examples 23-32.

Example 37: A method involving a wearable device, the method comprising:receiving data representing a first playback session swap input; basedon receiving the data representing the first playback session swapinput, identifying one or more source playback devices within a mediaplayback system that are (a) connected to a first wireless local areanetwork (LAN) and (b) playing back particular audio content in aplayback session, wherein the wearable playback device is connected tothe first wireless LAN via the 802.11-compatible network interface; andtransitioning the playback session from the determined one or moresource playback devices to the wearable playback device, whereintransitioning the playback session comprises (i) forming a firstsynchrony group including the wearable playback device and the one ormore source playback devices, wherein forming the first synchrony groupcauses the wearable playback device to start playing the particularaudio content of the playback session, and (ii) causing playback of theparticular audio content on the one or more source playback devices tostop.

Example 38: The method of example 37, wherein identifying the one ormore source playback devices comprises: identifying a set ofswap-eligible playback devices in the media playback system; causing theset of swap-eligible playback devices to emit respective audio chirpsthat identify the emitting swap-eligible playback devices; detecting,via the one or more microphones, the audio chirps emitted by one or moreswap-eligible playback devices; and selecting the one or more sourceplayback devices from among the one or more swap-eligible playbackdevices based on the audio chirp from the one or more source playbackdevices indicating that the one or more source playback devices arephysically nearest to the wearable playback device among the one or moreswap-eligible playback devices.

Example 39: The method of example 38: wherein the one or moremicrophones comprise one or more acoustic noise cancelling microphonescarried on one or more exterior surfaces of the one or more wearablehousings, and wherein detecting the audio chirps emitted by one or moreswap-eligible playback devices comprises: detecting the audio chirpsemitted by one or more swap-eligible playback devices via the one ormore acoustic noise cancelling microphones.

Example 40: The method of any preceding example 37-39, wherein selectingthe one or more source playback devices from among the one or moreswap-eligible playback devices comprises: comparing one or morerespective metrics of the detected audio chirps emitted by one or moreswap-eligible playback devices to determine that the one or more sourceplayback devices are physically nearest to the wearable playback deviceamong the one or more swap-eligible playback devices.

Example 41: The method of any preceding example 37-40, furthercomprising: while playing back audio content in the transitionedplayback session, receiving data representing a second playback sessionswap input; based on the second playback session swap input, identifyingone or more target playback devices within the media playback systemthat are connected to the first wireless LAN; and transitioning theplayback session from the determined one or more target playback devicesto the wearable playback device, wherein transitioning the playbacksession comprises (i) forming a second synchrony group including thewearable playback device and the one or more target playback devices,wherein forming the second synchrony group causes the one or more targetplayback devices to start playing the particular audio content of theplayback session, and (ii) removing the wearable playback device fromthe second synchrony group.

Example 42: The method of any preceding example 37-41, wherein one ormore wearable housings of the wearable playback device comprise atouch-sensitive region, and wherein receiving the data representing theplayback session swap input comprises receiving input data representinga touch-and-hold input on the touch-sensitive region.

Example 43: The method of any preceding example 37-42, wherein receivingthe data representing the playback session swap input comprisesreceiving, via the 802.11-compatible network interface from a controllerapplication on a mobile device, data representing instructions toperform a playback session swap.

Example 44: The method of any preceding example 37-43, wherein causingplayback of the particular audio content on the one or more sourceplayback devices to stop comprises: after forming the synchrony groupincluding the wearable playback device and one or more source devices,causing the one or more source devices to be removed from the synchronygroup.

Example 45: The method of any preceding example 37-44, wherein the oneor more source devices comprises a master playback device configured toplay back multi-channel audio, and wherein transitioning the playbacksession comprises: sending, via the 802.11-compatible network interfaceto the master playback device, data representing instructions to enter aswap mode; receiving, via the 802.11-compatible network interface to themaster playback device, data representing (i) a service set identifier(SSID) of a second wireless LAN, the second wireless LAN formed by themaster playback device and (ii) credentials for the second wireless LAN;disconnecting from the first wireless LAN and connecting to the secondwireless LAN via the 802.11-compatible network interface; and whileconnected to the second wireless LAN, receiving, via the802.11-compatible network interface, data representing (i) playbacktiming information for the first synchrony group and (ii) themulti-channel audio.

Example 45: The method of any preceding example 37-44, wherein thewearable playback device comprises: one or more network interfaces,wherein the one or more network interfaces comprises an802.11-compatible network interface; one or more transducers; one ormore amplifiers configured to drive the one or more transducers; one ormore batteries; one or more processors; one or more wearable housings,the one or more wearable housings carrying the one or more networkinterfaces, the one or more transducers, the one or more amplifiers, theone or more batteries, the one or more processors, and data storagehaving instructions stored thereon that are executable by the one ormore processors to cause the wearable playback device to perform themethod of any preceding example 37-44.

Example 46: The method of example 45, wherein one or more wearablehousings of the wearable playback device are formed into one of (a)headphones or (b) one or more earbuds.

Example 47: A system configured to perform the method of any of examples37-46.

Example 48: A device configured to perform the method of any of examples37-46.

Example 49: A tangible, non-transitory computer-readable media havingstored therein instructions executable by one or more processors toperform the method of any of examples 37-46.

Example 50: A method involving a first playback device and a secondplayback device, the method comprising: while in a home theater mode,playing back audio received via the audio input interface, wherein thefirst playback device is a master device of a first synchrony group;while in the home theater mode, receiving, via an 802.11-compatiblenetwork interface from the second playback device, data representinginstructions to transition to a swap mode; based on receiving the datarepresenting the instructions to enter the swap mode with the secondplayback device, transitioning from the home theater mode to the swapmode with the second playback device, wherein transitioning from thehome theater mode to the swap mode comprises: transitioning the802.11-compatible network interface from operating as a node in a meshnetwork to operating as an access point that forms a first wirelesslocal area network (LAN) in a first wireless frequency band; sending,via the 802.11-compatible network interface to the second playbackdevice, data representing (i) a service set identifier (SSID) of thefirst wireless LAN and (ii) credentials for the first wireless LAN;after connecting to the first wireless LAN formed by the first playbackdevice, forming a second synchrony group that includes the firstplayback device and the second playback device; receiving, via an802.11-compatible network interface to the second playback device, datarepresenting (i) playback timing information for the second synchronygroup and (ii) the audio, wherein the second playback device plays backthe audio; and after joining the second synchrony group, playing backthe audio in synchrony with the first playback device, wherein the firstplayback device mutes playback of the audio while the second playbackdevice plays back the audio.

Example 51: The method of example 50, wherein the first synchrony groupincludes the first playback device and one or more satellite playbackdevices, wherein the audio comprises multi-channel audio, and whereinplaying back the multi-channel audio comprises sending, via the802.11-compatible network interface to the one or more satelliteplayback devices, data representing (i) playback timing information forthe first synchrony group and (ii) respective channels of themulti-channel audio, and wherein transitioning from the home theatermode to the swap mode further comprises: causing the one or moresatellite playback devices to (i) connect to a second wireless LAN in asecond wireless frequency band and (ii) leave the first synchrony group.

Example 52: The method of example 51, further comprising: detecting anevent representing a trigger to transition from operating in the swapmode to operating in the home theater mode; after detecting the event,transitioning from the swap mode to the home theater mode, whereintransitioning from the swap mode to the home theater mode comprises:causing the one or more satellite playback devices to connect to themesh network; transitioning the 802.11-compatible network interface fromoperating as the access point to operating as the node in the meshnetwork; and re-forming the first synchrony group that includes thefirst playback device and the one or more satellite playback devices;operating in the home theater mode, sending, via the 802.11-compatiblenetwork interface to the one or more satellite playback devices, datarepresenting (i) playback timing information for the first synchronygroup and (ii) respective channels of the multi-channel audio; andplaying back the one or more channels of the multi-channel audio insynchrony with the one or more satellite playback devices playing backthe respective channels of the multi-channel audio.

Example 53: The method of example 52, wherein detecting the eventcomprises detecting that the first wireless playback device hasdisconnected from the first wireless LAN.

Example 54: The method of any preceding example 50-53, wherein the audioreceived via the audio input interface comprises a surround sound audiotrack, and wherein the functions further comprise down-mixing thesurround sound audio track to a stereo audio track, and wherein sendingthe data representing the audio comprises sending data representing thestereo audio track to the second playback device.

Example 55: The method of any preceding example 50-54, furthercomprising: while in the swap mode, receiving, via the 802.11-compatiblenetwork interface from a third playback device, data representinginstructions to transition to the swap mode; based on receiving, fromthe third playback device, the data representing the instructions toenter the swap mode, causing the third playback device to join thesecond synchrony group, wherein causing the third playback device tojoin the second synchrony group comprises: sending, via the802.11-compatible network interface to the third playback device, datarepresenting (i) the SSID of the first wireless LAN and (ii) credentialsfor the first wireless LAN; after the third playback device connects tothe first wireless LAN formed by the first playback device, adding thethird playback device to the second synchrony group that includes thefirst playback device and the second playback device; and sending, viathe 802.11-compatible network interface to the third playback device,data representing (i) the playback timing information for the secondsynchrony group and (ii) the audio, wherein the third playback deviceplays back the audio in synchrony with the second playback device.

Example 56: The method of any preceding example 50-55, furthercomprising: while in a music mode, playing back audio content receivedvia the one or more network interfaces; while playing back the audiocontent in the music mode, receiving, via the 802.11-compatible networkinterface from the second playback device, data representinginstructions to form a third synchrony group with the second playbackdevice; forming the third synchrony group with the second playbackdevice, wherein forming the third synchrony group with the secondplayback device configures the first playback device to play back theaudio content in synchrony with the second playback device; and afterforming the third synchrony group with the second playback device,leaving the third synchrony group, wherein the second playback device isthe master device of the third synchrony group.

Example 57: The method of example 56, further comprising: receiving datarepresenting a playback session swap trigger; based on receiving thedata representing the playback session swap trigger, identifying one ormore source playback devices within a media playback system that playingback particular audio content in a playback session, wherein identifyingthe one or more source devices comprises: identifying a set ofswap-eligible playback devices in the media playback system, the setincluding the first playback device; causing the set of swap-eligibleplayback devices to emit respective audio chirps that identify theemitting swap-eligible playback devices; detecting, via the one or moremicrophones, the audio chirps emitted by one or more swap-eligibleplayback devices from the set of swap-eligible playback devices, the oneor more swap-eligible playback devices including the first playbackdevice; and selecting the first playback device as the one or moresource playback devices from among the one or more swap-eligibleplayback devices based on the audio chirp from the first playback deviceindicating that the first playback device is physically nearest to thesecond playback device among the one or more swap-eligible playbackdevices.

Example 58: The method of example 56, further comprising: while in themusic mode and before receiving the data representing instructions toform the third synchrony group with the second playback device,receiving, via the 802.11-compatible network interface from the secondplayback device, data representing instructions to emit a particularaudio chirp; and based on receiving the data representing instructionsto emit a particular audio chirp, emitting the particular audio chirpvia the one or more transducers.

Example 59: The method of any preceding example 50-58, wherein thesecond playback device comprises one or more housings, and wherein theone or more housings are formed into one of (a) headphones or (b) a setof earbuds.

Example 60: The method of any preceding example 50-59, wherein the firstplayback device comprises: an audio input interface; one or more networkinterfaces, wherein the one or more network interfaces comprises an802.11-compatible network interface; one or more transducers; one ormore amplifiers configured to drive the one or more amplifiers; and ahousing carrying the an audio input interface, the one or more networkinterfaces, the one or more transducers, the one or more amplifiers, theone or more processors, and data storage having instructions storedthereon that are executable by the one or more processors to cause thesoundbar-type playback device to perform the method of any precedingexample 50-59.

Example 61: The method of any preceding example 50-60, wherein thesecond playback device comprises: one or more network interfaces,wherein the one or more network interfaces comprises an802.11-compatible network interface; one or more transducers; one ormore amplifiers configured to drive the one or more transducers; one ormore batteries; one or more processors; a housing carrying the one ormore network interfaces, the one or more transducers, the one or moreamplifiers, the one or more batteries, the one or more processors, anddata storage having instructions stored thereon that are executable bythe one or more processors to cause the wearable playback device toperform the method of any preceding example 50-60.

Example 62: A system configured to perform the method of any of examples50-61.

Example 64: A device configured to perform the method of any of examples50-61.

Example 65: A tangible, non-transitory computer-readable media havingstored therein instructions executable by one or more processors toperform the method of any of examples 50-61.

1. A system comprising: a non-wearable playback device comprising atleast one audio transducer; a wearable playback device; at least oneprocessor; and at least one non-transitory computer-readable mediumcomprising program instructions that are executable by the at least oneprocessor such that the system is configured to: receive datarepresenting surround sound audio via a data interface; play back afirst portion of the surround sound audio in a playback session on thenon-wearable playback device via the at least one audio transducer;during the playback session, receive data representing a playbacksession swap command; according to the playback session swap command,transition the playback session from the non-wearable playback device tothe wearable playback device, wherein the instructions that areexecutable by the at least one processor such that the system isconfigured to transition the playback session from the non-wearableplayback device to the wearable playback device comprise instructionsthat are executable by the at least one processor such that the systemis configured to: form a synchrony group including the non-wearableplayback device as a group coordinator of the synchrony group and thewearable playback device as a group member of the synchrony group,wherein formation of the synchrony group causes the wearable playbackdevice to start playing the surround sound audio in the playbacksession; and mute playback on the non-wearable playback device; andcause the wearable playback device to continue playback of the surroundsound audio in the transitioned playback session, wherein theinstructions that are executable by the at least one processor such thatthe system is configured to cause the non-wearable playback device tocontinue playback of the surround sound audio in the transitionedplayback session comprise instructions that are executable by the atleast one processor such that the system is configured to: send, via anetwork interface of the non-wearable playback device, data representinga second portion of the surround sound audio to the wearable playbackdevice for playback.
 2. The system of claim 1, wherein the instructionsthat are executable by the at least one processor such that the systemis configured to cause the wearable playback device to continue playbackof the surround sound audio in the transitioned playback sessioncomprise instructions that are executable by the at least one processorsuch that the system is configured to: send, in accordance withconfiguration of the non-wearable playback device as the groupcoordinator, playback timing information via the network interface ofthe non-wearable playback device.
 3. The system of claim 1, wherein thesurround sound audio comprises three or more audio channels, and whereinthe instructions that are executable by the at least one processor suchthat the system is configured to cause the wearable playback device tocontinue playback of the surround sound audio in the transitionedplayback session comprise instructions that are executable by the atleast one processor such that the system is configured to: down-mix, viaone or more processors of the non-wearable playback device, the three ormore audio channels of the surround sound audio to a first audio channeland a second audio channel.
 4. The system of claim 3, wherein theinstructions that are executable by the at least one processor such thatthe system is configured to cause the wearable playback device tocontinue playback of the surround sound audio in the transitionedplayback session comprise instructions that are executable by the atleast one processor such that the system is configured to: cause thenon-wearable playback device to play back (i) the first audio channelvia at least one first audio traducer and (ii) the second audio channelvia at least one second audio traducer.
 5. The system of claim 1,wherein the wearable playback device comprises a touch-sensitive userinterface, and wherein the instructions that are executable by the atleast one processor such that the system is configured to receive thedata representing the playback session swap command compriseinstructions that are executable by the at least one processor such thatthe system is configured to: receive, via the touch-sensitive userinterface, input data representing the playback session swap command. 6.The system of claim 1, wherein the instructions that are executable bythe at least one processor such that the system is configured to receivethe data representing the playback session swap command compriseinstructions that are executable by the at least one processor such thatthe system is configured to: receive, via the network interface of thenon-wearable playback device, the data representing the playback sessionswap command.
 7. The system of claim 1, wherein the data interfacecomprises a high-definition multimedia interface (HDMI) port, andwherein the instructions that are executable by the at least oneprocessor such that the system is configured to receive the datarepresenting the surround sound audio via the data interface compriseinstructions that are executable by the at least one processor such thatthe system is configured to: receive, via the HDMI port, the datarepresenting the surround sound audio.
 8. The system of claim 1, whereinthe data interface comprises the network interface of the non-wearableplayback device, and wherein the instructions that are executable by theat least one processor such that the system is configured to receive thedata representing the surround sound audio via the data interfacecomprise instructions that are executable by the at least one processorsuch that the system is configured to: receive, via the networkinterface of the non-wearable playback device, the data representing thesurround sound audio.
 9. The system of claim 1, wherein the at least onenon-transitory computer-readable medium further comprises programinstructions that are executable by the at least one processor such thatthe system is configured to: during the playback session, receive datarepresenting a playback session join command; and according to theplayback session join command, add an additional wearable playbackdevice to the playback session, wherein the instructions that areexecutable by the at least one processor such that the system isconfigured to add the additional wearable playback device to theplayback session comprise instructions that are executable by the atleast one processor such that the system is configured to: add theadditional wearable playback device to the synchrony group as anadditional group member of the synchrony group, wherein additional ofthe additional wearable playback device to the synchrony group causesthe additional wearable playback device to start playing the surroundsound audio in the playback session.
 10. The system of claim 1, whereinthe wearable playback device comprises one or more housings formed intoat least one of (a) headphones or (b) earbuds.
 11. A non-wearableplayback device comprising: at least one audio transducer; a networkinterface; at least one processor; and at least one non-transitorycomputer-readable medium comprising program instructions that areexecutable by the at least one processor such that the non-wearableplayback device is configured to: receive data representing surroundsound audio via a data interface; play back a first portion of thesurround sound audio in a playback session on the non-wearable playbackdevice via the at least one audio transducer; during the playbacksession, receive data representing a playback session swap command;according to the playback session swap command, transition the playbacksession from the non-wearable playback device to a wearable playbackdevice, wherein the instructions that are executable by the at least oneprocessor such that the non-wearable playback device is configured totransition the playback session from the non-wearable playback device tothe wearable playback device comprise instructions that are executableby the at least one processor such that the non-wearable playback deviceis configured to: form a synchrony group including the non-wearableplayback device as a group coordinator of the synchrony group and thewearable playback device as a group member of the synchrony group,wherein formation of the synchrony group causes the wearable playbackdevice to start playing the surround sound audio in the playbacksession; and mute playback on the non-wearable playback device; andcause the wearable playback device to continue playback of the surroundsound audio in the transitioned playback session, wherein theinstructions that are executable by the at least one processor such thatthe non-wearable playback device is configured to cause the non-wearableplayback device to continue playback of the surround sound audio in thetransitioned playback session comprise instructions that are executableby the at least one processor such that the non-wearable playback deviceis configured to: send, via a network interface of the non-wearableplayback device, data representing a second portion of the surroundsound audio to the wearable playback device for playback.
 12. Thenon-wearable playback device of claim 11, wherein the instructions thatare executable by the at least one processor such that the non-wearableplayback device is configured to cause the wearable playback device tocontinue playback of the surround sound audio in the transitionedplayback session comprise instructions that are executable by the atleast one processor such that the non-wearable playback device isconfigured to: send, in accordance with configuration of thenon-wearable playback device as the group coordinator, playback timinginformation via the network interface of the non-wearable playbackdevice.
 13. The non-wearable playback device of claim 11, wherein thesurround sound audio comprises three or more audio channels, and whereinthe instructions that are executable by the at least one processor suchthat the non-wearable playback device is configured to cause thewearable playback device to continue playback of the surround soundaudio in the transitioned playback session comprise instructions thatare executable by the at least one processor such that the non-wearableplayback device is configured to: down-mix, via one or more processorsof the non-wearable playback device, the three or more audio channels ofthe surround sound audio to a first audio channel and a second audiochannel.
 14. The non-wearable playback device of claim 13, wherein theinstructions that are executable by the at least one processor such thatthe non-wearable playback device is configured to cause the wearableplayback device to continue playback of the surround sound audio in thetransitioned playback session comprise instructions that are executableby the at least one processor such that the non-wearable playback deviceis configured to: cause the wearable playback device to play back (i)the first audio channel via at least one first audio traducer and (ii)the second audio channel via at least one second audio traducer.
 15. Thenon-wearable playback device of claim 11, wherein the instructions thatare executable by the at least one processor such that the non-wearableplayback device is configured to receive the data representing theplayback session swap command comprise instructions that are executableby the at least one processor such that the non-wearable playback deviceis configured to: receive, via the network interface of the non-wearableplayback device, the data representing the playback session swapcommand.
 16. The non-wearable playback device of claim 11, wherein thedata interface comprises a high-definition multimedia interface (HDMI)port, and wherein the instructions that are executable by the at leastone processor such that the non-wearable playback device is configuredto receive the data representing the surround sound audio via the datainterface comprise instructions that are executable by the at least oneprocessor such that the non-wearable playback device is configured to:receive, via the HDMI port, the data representing the surround soundaudio.
 17. The non-wearable playback device of claim 11, wherein thedata interface comprises the network interface of the non-wearableplayback device, and wherein the instructions that are executable by theat least one processor such that the non-wearable playback device isconfigured to receive the data representing the surround sound audio viathe data interface comprise instructions that are executable by the atleast one processor such that the non-wearable playback device isconfigured to: receive, via the network interface of the non-wearableplayback device, the data representing the surround sound audio.
 18. Thenon-wearable playback device of claim 11, wherein the at least onenon-transitory computer-readable medium further comprises programinstructions that are executable by the at least one processor such thatthe non-wearable playback device is configured to: during the playbacksession, receive data representing a playback session join command; andaccording to the playback session join command, add an additionalwearable playback device to the playback session, wherein theinstructions that are executable by the at least one processor such thatthe non-wearable playback device is configured to add the additionalwearable playback device to the playback session comprise instructionsthat are executable by the at least one processor such that thenon-wearable playback device is configured to: add the additionalwearable playback device to the synchrony group as an additional groupmember of the synchrony group, wherein additional of the additionalwearable playback device to the synchrony group causes the additionalwearable playback device to start playing the surround sound audio inthe playback session.
 19. At least one non-transitory computer-readablemedium comprising program instructions that are executable by at leastone processor such that a system is configured to: receive datarepresenting surround sound audio via a data interface; play back afirst portion of the surround sound audio in a playback session on anon-wearable playback device via at least one audio transducer; duringthe playback session, receive data representing a playback session swapcommand; according to the playback session swap command, transition theplayback session from the non-wearable playback device to a wearableplayback device, wherein the instructions that are executable by the atleast one processor such that the system is configured to transition theplayback session from the non-wearable playback device to the wearableplayback device comprise instructions that are executable by the atleast one processor such that the system is configured to: form asynchrony group including the non-wearable playback device as a groupcoordinator of the synchrony group and the wearable playback device as agroup member of the synchrony group, wherein formation of the synchronygroup causes the wearable playback device to start playing the surroundsound audio in the playback session; and mute playback on thenon-wearable playback device; and cause the wearable playback device tocontinue playback of the surround sound audio in the transitionedplayback session, wherein the instructions that are executable by the atleast one processor such that the system is configured to cause thenon-wearable playback device to continue playback of the surround soundaudio in the transitioned playback session comprise instructions thatare executable by the at least one processor such that the system isconfigured to: send, via a network interface of the non-wearableplayback device, data representing a second portion of the surroundsound audio to the wearable playback device for playback.
 20. The atleast one non-transitory computer-readable medium of claim 19, whereinthe at least one non-transitory computer-readable medium furthercomprises program instructions that are executable by the at least oneprocessor such that the system is configured to: during the playbacksession, receive data representing a playback session join command; andaccording to the playback session join command, add an additionalwearable playback device to the playback session, wherein theinstructions that are executable by the at least one processor such thatthe system is configured to add the additional wearable playback deviceto the playback session comprise instructions that are executable by theat least one processor such that the system is configured to: add theadditional wearable playback device to the synchrony group as anadditional group member of the synchrony group, wherein additional ofthe additional wearable playback device to the synchrony group causesthe additional wearable playback device to start playing the surroundsound audio in the playback session.